#### Solve the questions given below

The *Trick* given is only to help memorize the answer. That is **NOT** a correct way to solve these questions.

- A train 75m long overtook a person who was walking at the rate of 15/2 sec. Simultaneously, it overtook the second person and passed him at 27/4 sec. At what rate was the second person traveling?

Answer:

**2km/h***Trick:*Denominator - 2 and 4, or 4 / 2 = 2 km/h - Two trains 141m and 119m in length are walking in opposite directions. One at a rate of 30 km/h and the other one at 42 km/h. Calculate the time in which both the trains will be completely far away from each other?

Answer:

**13sec***Trick:*excessive 1, select 1. 42-30 = 12 + 1 = 13 - A train which is moving at an average speed of 40 km/h reaches its destination on time. When its average speed reduces to 35 km/h, the train reaches the destination 15 min. late. Calculate the distance traveled by the train.

Answer:

**70km***Trick:*40 + 35 = 75 - 5 from 15 = 70 - The total age of Ankit, Nitin, and Abhay is 96 years. Five years after the ratio of their ages will be 2:3:4. Find the present age of Abhay.

Answer:

**41 years***Trick:*96 - 5years = 91. 91 / 2 = 40 remainder 1. 40 + 1 = 41 - Five years ago, the ratio of Omkar and Nikhil was 8:7. Three years hence, the ratio of their ages will be 12:11. Calculate Nikhil's present age.

Answer:

**19 years***Trick:*8 + 11 = 19 - The present ages of three friends are in the ratio 3:5:7. Four years ago, the sum of their ages was 48. Find the present ages of these friends.

Answer:

**12, 20, 28 years***Trick:*4 years... and 3 ratios. Multiply them. 3 x 4 = 12, 5 x 4 = 20, 7 x 4 = 28 - The sum of the ages of A and B is 38 years. After eight years, the age of B is two years more than A. Calculate the age of B before five years.

Answer:

**15 years***Trick:*38 - 8years = 30 / 2 years = 15. - The difference between the value of a number increased by 25% and the value of the original number decreased by 30% is 22. What is the original number?

Answer:

**40***Trick:*Select 30. 3 times 2 is present. Select number with most 2's. 22. 2x2 = 4. Left digit is 0 from 30. Thus, 40. - Mr. Roy spent rs.44620 on Diwali shopping, rs.32764 on buying a laptop, and the remaining 32% of the total amount he had as cash with him. What is the total amount in all he had with him?

Answer:

**113800**Let's denote the total amount Mr. Roy had as 'T'.

According to the problem, Mr. Roy spent Rs.44620 on Diwali shopping, Rs.32764 on buying a laptop, and kept the remaining 32% of 'T' with him.

So, the equation would be:

T = 44620 + 32764 + 0.32T

We can simplify this equation to:

0.68T = 44620 + 32764

Solving this equation for 'T', we can find the total amount Mr. Roy had with him.

T = \(\frac{{44620 + 32764}}{{0.68}}\)

= 113800

- If z = x^2/y and x and y are both increased in value by 10%, find the percentage change in the value of x.

Answer:

**10%***Trick:*Direct 10% - Arif got 30% of the maximum marks in an examination yet failed by 10 marks. However, Paul who took the same examination got 40% of the total marks and got 15 marks more than the passing marks. What were the passing marks in the examination?

Answer:

**85 marks***Trick:*Digits of 30% + 70% + 15 = 85 - If the manufacturer gains 10%, the wholesale dealer gains 15%, and the retailer gains 25%, then find the cost of production of a table if the retail price of the table is rs.1265.

Answer:

**800***Trick:*Select first digits of percentages: 1 + 1 + 2 = 4. eqn. 1; 2 times 5? so add 2 more - 6. selected 5 so 65. or 1200 - 465 from eqn1_eqn2 = 800 - An article is sold at a certain price. By selling it at 2/3 of that price, one loses 10%. Find the gain percent at the original price.

Answer:

**35***Trick:*Select 2/3. Denominator_and_addition_of_both 3(3+2) = 35 - If the selling price of an article is 4/3 of its cost price, calculate the profit in the transaction.

Answer:

**33.33% or $33\dfrac{1}{3}\%$***Trick:*4 times 3 = 3333 with a dot in between 33.33 or its fractional counterpart - A silver bracelet is sold for rs.14500 at a loss of 20%. What is the cost price of the bracelet?

Answer:

**18125***Trick:*Select 4 from 14500 and keep 1 as it is for final number. Select 2 from 20% = 4 x 2 = 8. Therefore 18 and there is 2 so square 5 two times. or 125. Thus, 18125 - A&B can do a piece of work in 45 days and 40 days. They began the work together, but A leaves after some days, and B finished the remaining work in 23 days. After how many days did A leave the work?

Answer:

**9 days***Trick:*Select 45. 4 + 5 = 9 - Kamal can do a piece of work in 15 days. Bimal is 50% more efficient than Kamal. The number of days Bimal will take to do the same piece of work is?

Answer:

**10 days***Trick:*Select 15. Select 5 from 5. 15 - 5 = 10 - 8 men can complete a piece of work in 20 days. 8 women can complete the same work in 32 days. In how many days will 5 men and 8 women together complete the work?

Answer:

**16 days***Trick:*8 men + 8 women = 16 - By walking 3/4th of his usual speed, a man reaches his office 20 min later than his usual time. Find the usual time taken by him to reach the office.

Answer:

**x=0(not possible), T=1***Trick:*Select 3 from 3/4. 3 times 20 is 60 or 60 min or 1 hour. - Places A&B are 100km apart on a highway. One car starts from A, and another from B at the same time. If the cars travel in the same direction at different speeds, they meet in 5 hrs. If they travel towards each other, they meet in 1 hr. What are the speeds of the two cars?

Answer:

**60kmph and 40kmph***Trick:*5+1 = 6. 5-1 = 4. there are 2 zero's. Diseminate them. So 60 and 40. - 2 women and 5 men can together finish the work in 4 days, while 3 women and 6 men can finish it in 3 days. Find the time taken by 1 woman alone to finish the work and also that taken by 1 man alone.

Answer:

**1 women alone = 18**

1 man alone = 36*Trick:*Select 3 women and 6 men = 18. Total women in question = 6 women or 6 x 6 men = 36 - Two water taps together can fill a tank in 75/8 hrs. The tap of the larger diameter takes 10 hrs. less than the smaller one to fill the tank separately. Find the time in which each tap can separately fill the tank?

Answer:

**Larger Tap: 15 hours and Smaller Tap 25 hours.***Trick:*Select 75/8. Smaller tank = subtract smaller digit. Larger = subtract larger digit. 5 remain contant at 1's place. 7-5 = 2 or 25. 8-7 = 1 or 15. - Three pipes A, B & C can fill the tank in 3 hrs., 4 hrs. resp. While C can empty the completely filled tank in 1 hr. If the pipes are opened at 3, 4, 5 pm, at what time will the tank be completely empty?

Answer:

**7:12 PM or in 2 hours 12 minutes***Trick:*3 + 4 = 7 and 3 + 4 + 5 = 12. Therefore 7:12. - In 1 min., 3/7th of a bucket is filled. The rest of the bucket can be filled in how many mins.?

Answer:

**$\dfrac{4}{3}$ min***Trick:*3 + 4 = 7 and 7 - 4 = 3. So 4 / 3 - Water flows through a cylindrical pipe of internal diameter 7cm at the rate of 5m/sec. Calculate the time in mins. that the pipe would take to fill an empty rectangular tank with dimensions 4*3*2.31m.

Answer:

**24 min***Trick:*Multiply dimensions: 4 x 3 = 12 x 2 = 24 - The speed of the boat traveling downstream is 32 km/hr, whereas when upstream is 28 km/hr. What is the speed of the boat in still water and the speed of the stream?

Answer:

**Speed of Boat: 30km/h Speed of stream: 2km/hr***Trick:*32 and 28. Average 30. Both have difference of 2, so, 30 and 2. - A motorboat can travel at 10 km/hr. in still water. It traveled 91 km downstream in a river and then returned altogether in 20 hrs. Find the rate of the river?

Answer:

**3km/hr***Trick: 91 / 10 + 20 = 3* - A boat goes 30 km upstream and 44 km downstream in 10 hrs. In 13 hrs, it has to go 40 km upstream and 55 km downstream. Determine the speed of the stream and the speed of the boat in still water?

Answer:

**Speed of boat = 8km/h Speed of Stream: 3km/hr***Trick:*Take 44. add digits. 4 + 4 = 8. 2 hours are close by. 13 - 10 = 3. - If the difference of the squares of the sum of two numbers and the difference of that number is 624, then the product of those numbers is?

Answer:

**156***Trick:*1 + 5 = 6. and 2 + 4 = 6. So 156 - Find the value of the squares of the sum of the integers and their difference when the sum of their individual squares is 45.

Answer:

**90***Trick:*45 x number of square or 2 = 90 - The product of Raman's age five years ago and nine years from now will be 15. Find Raman's present age?

Answer:

**6***Trick: 15-9 = 6* - A journey of 192 km from Bombay to Pune takes 2 hours less by a fast train than by a slow train. If the average speed of the slow train is 16 km/hr less than that of the fast train, find the average speed of the train.

Answer:

**48km/h***Trick:*Take last digits of 2 and 16. 6-2 = 4, 6+2=8; 48. - The sum of the number and its reciprocal is 17/4. Find the number?

Answer:

**4 or $\dfrac{1}{4}$***Trick:*The problem is asking to find a number \(x\) such that the sum of the number (\(x\)) and its reciprocal (\(\frac{1}{x}\)) equals \(\frac{17}{4}\). This can be written as an equation:

\(x + \frac{1}{x} = \frac{17}{4}\)

To make the problem easier to solve, let's multiply every term by \(4x\) to get rid of the fractions and the denominator:

\(4x^2 + 4 = 17x\)

Then, rearrange the equation to get a quadratic equation:

\(4x^2 - 17x + 4 = 0\)

Now, you can solve the quadratic equation using the quadratic formula:

\(x = \frac{{17 \pm \sqrt{{(17)^2 - 4 \cdot 4 \cdot 4}}}}{2 \cdot 4}\)

\(x = \frac{{17 \pm \sqrt{{289 - 64}}}}{8}\)

\(x = \frac{{17 \pm \sqrt{{225}}}}{8}\)

\(x = \frac{{17 \pm 15}}{8}\)

The solutions are:

\(x_1 = \frac{{17 + 15}}{8} = \frac{32}{8} = 4\)

\(x_2 = \frac{{17 - 15}}{8} = \frac{2}{8} = 0.25\)

So, the number could be either 4 or 0.25.

- The length of a rectangular plot is 8 m greater than its breadth. If the area of the plot is 308 m², find the length and the breadth of the plot?

Answer:

**Length = 22m and Breadth = 14m***Trick:*Divide 308 by 8. First comes 8 x 3 = 24 to reduce 30.. 2 is first digit of first number. 4 is last digit of last number. Do rever counting of 1 and 2 R to L. 22, 14 - A plane left 30 min later than the scheduled time, and in order to reach its destination 1500 km away in time, it has to increase its speed by 250 km/hr from its usual speed. Find the usual speed?

Answer:

**750km/h***Trick:*250 x 3 = 750. - Seven times a two-digit number is equal to 4 times the number obtained by reversing the order of digits, and the sum of the digits of the number is 3. Find the number?

Answer:

**12**Let's denote the tens digit as

*a*and the units digit as*b*. Hence, the two-digit number is*10a + b*.According to the problem, we have two conditions:

- Seven times the original number is equal to four times the number obtained by reversing the digits. We can express this as
*7*(10a + b) = 4*(10b + a)*. - The sum of the digits of the number is 3, which gives us
*a + b = 3*.

We now have a system of two equations with two variables, which we can solve.

From the first equation, we can simplify to

*70a + 7b = 40b + 4a*, which simplifies to*66a = 33b*. Simplifying this further gives*2a = b*.Now substitute

*2a*for*b*in the second equation (*a + b = 3*) to solve for*a*:*a + 2a = 3**3a = 3**a = 1*Substitute

*a = 1*into the equation*2a = b*to find*b*:*2*1 = b**b = 2*So, the original two-digit number is 12.

- Seven times the original number is equal to four times the number obtained by reversing the digits. We can express this as
- A fraction is such that if the numerator is multiplied by 3 and the denominator is reduced by 3, we get 18/11. But if the numerator is increased by 8 and the denominator is doubled, we get 2/5. Find the fraction?

Answer:

**$\dfrac{12}{25}$***Trick:*Select 2/5. Start counting from 1 for numerator and 2 for denominator. 12/25 - Anmol had 10p, 25p, 50p coins in the ratio of 10:8:9 respectively. After giving Rs. 20 to his mother, he has Rs. 40. How many 50p coins did he have?

Answer:

**72***Trick:*50p + 20Rs = 70 + 2 = 72 - The cost price of 2 shirts and 3 jeans is Rs. 2200, and the cost price of 2 jeans and 4 shirts is Rs. 2400. Find the ratio between the cost price of the jeans and the shirts.

Answer:

**Ratio is 10 : 7** - The difference between the 2 positive numbers is 10, and the ratio between them is 5:3. Find the product of the two numbers?

Answer:

**375***Trick:*Select 3:5 and 2. 5+2 = 7. Reverse the reciprocal order. and 7 in between. 375 - The ratio between the two numbers is 3:4, and their LCM is 180. Find the numbers.

Answer:

**45 and 60***Trick:*60 x 3 - 180; 45 x 4 = 180. - If a:b = 7:5 and c:d = 2a:3b, then find the value of ac:bd?

Answer:

**$\dfrac{14}{15}$***Trick:*7 x 2 = 14; 5 x 3 = 15 - 78% of 150 + 168 ÷ √144 - 120% of 45 - ?=19*√9

Answer:

**20***Trick:*19 + 1 = 20 - 380 + 620 - 190% of 820= ? - 120*√25

Answer:

**42***Trick:*Four times 2 is present in the question. 42 - 57*√81 - 492 + 920 ÷ √400 + ? = √4489

Answer:

**0** - 40% of 375 ÷ cube root of 512 x 30 = 4500 ÷ ?

Answer:

**8***Trick:*Select 2 from 512. 2^3 = 8 - (2477.68 + 1254.87 - 3647.89) = ? x 13 - 84.34

Answer:

**13***Trick:*The only number without decimal = 13 - 32.5% of 1388 - √4096 ÷ 4 x √529 = ?

Answer:

**83.10***Trick:*Select 1388. reverse it. removee duplicate. 83.1 - 42.5% of 750 = ?% of 43 - 26% of ?

Answer:

**1875***Trick:*4 x 2 = 8 and 75 from 750 = 1875