Mathematics

10 questions loaded

History

Log in to practise this subject

These are sample questions with their answers. Log in to attempt them, track your accuracy, earn coins and save every session to your history.

Sample questions

A free sample. Log in for your full daily practice.

1.

A car travels from city A to city B at an average speed of 50 km/h and returns at an average speed of 40 km/h. What is the average speed of the car for the entire trip?

  • A

    42.5 km/h

  • B

    44.4 km/h

  • C

    45 km/h

  • D

    46.2 km/h

Explanation

Let the distance between city A and city B be 'd'. Then, the time taken to travel from A to B = d/50 and the time taken to travel from B to A = d/40. The total time taken = d/50 + d/40 = (4d + 5d)/200 = 9d/200. The total distance traveled = 2d. The average speed = total distance/total time = 2d/(9d/200) = 400/9 km/h = 44.4 km/h.

2.

A can do a piece of work in 10 days, B can do it in 12 days, and C can do it in 15 days. How many days will it take for A, B, and C to complete the work together?

  • A

    4 days

  • B

    5 days

  • C

    6 days

  • D

    8 days

Explanation

First, find the individual rates of work for A, B, and C. A's rate = 1/10, B's rate = 1/12, and C's rate = 1/15. Then, add their rates to get the combined rate: 1/10 + 1/12 + 1/15 = 6/60 + 5/60 + 4/60 = 15/60 = 1/4. So, together they can complete the work in 4 days.

3.

A and B can do a piece of work in 12 days and 15 days respectively. If they work together for 5 days, what is the fraction of work left?

  • A

    1/6

  • B

    1/4

  • C

    1/3

  • D

    1/2

Explanation

Let the total work be 1 unit. Then, A's rate of work = 1/12 and B's rate of work = 1/15. When they work together, their combined rate = 1/12 + 1/15 = 9/60 = 3/20. In 5 days, they complete 5 * (3/20) = 3/4 of the work. So, the fraction of work left = 1 - 3/4 = 1/4.

4.

Find the value of x in the equation 2^x = 32

  • A

    3

  • B

    4

  • C

    5

  • D

    6

Explanation

We know that 2^5 = 32. Therefore, x must be 5.

5.A boat travels 30 km upstream in 3 hours and 20 km downstream in 2 hours. What is the speed of the boat in still water?
  • A5 km/h
  • B6 km/h
  • C7.5 km/h
  • D10 km/h

Explanation

Let the speed of the boat in still water be 'b' and the speed of the stream be 's'. Then, the speed upstream = b - s and the speed downstream = b + s. Using the given information, we can write the equations: 30/(b-s) = 3 and 20/(b+s) = 2. Solving these equations, we get b = 7.5 km/h.
6.

A merchant buys an article at a discount of 10% and sells it at a profit of 20%. What is the overall profit percentage?

  • A

    8%

  • B

    10%

  • C

    12%

  • D

    15%

Explanation

Let the cost price of the article be Rs. 100. After a discount of 10%, the merchant buys it for Rs. 90. Selling it at a 20% profit, the selling price is 90 + 0.2 * 90 = Rs. 108. The overall profit is 108 - 100 = Rs. 8, which is 8% of the cost price.

7.A boat travels 24 km downstream in 2 hours and 16 km upstream in 4 hours. What is the speed of the stream?
  • A1 km/h
  • B2 km/h
  • C2.5 km/h
  • D3 km/h

Explanation

Let the speed of the boat in still water be 'b' and the speed of the stream be 's'. Then, the speed downstream = b + s and the speed upstream = b - s. Using the given information, we can write the equations: 24/(b+s) = 2 and 16/(b-s) = 4. Solving these equations, we get s = 2 km/h.
8.

A mixture of two liquids A and B is made by mixing 4 parts of A with 3 parts of B. If the price of A is Rs. 50 per liter and the price of B is Rs. 75 per liter, what is the average price of the mixture?

  • A

    54.55 Rs/liter

  • B

    56.25 Rs/liter

  • C

    57.5 Rs/liter

  • D

    60.71 Rs/liter

Explanation

The total cost of the mixture = (4 * 50) + (3 * 75) = 200 + 225 = 425. The total quantity of the mixture = 4 + 3 = 7 liters. The average price of the mixture = total cost/total quantity = 425/7 = 60.71 Rs/liter.

9.

Two partners, X and Y, invest in a business in the ratio 2:3. If X invests Rs. 20000, what is the amount invested by Y?

  • A

    Rs. 20000

  • B

    Rs. 25000

  • C

    Rs. 30000

  • D

    Rs. 35000

Explanation

The ratio of their investments is 2:3. Let Y's investment be 3x. Then, X's investment is 2x. Since X invests Rs. 20000, 2x = 20000, which means x = 10000. So, Y's investment is 3x = 3 * 10000 = Rs. 30000.

10.A boat travels 30 km downstream in 2 hours and 20 km upstream in 4 hours. What is the speed of the boat in still water?
  • A5 km/h
  • B6 km/h
  • C7.5 km/h
  • D10 km/h

Explanation

Let the speed of the boat in still water be 'b' and the speed of the stream be 's'. Then, the speed downstream = b + s and the speed upstream = b - s. Using the given information, we can write the equations: 30/(b+s) = 2 and 20/(b-s) = 4. Solving these equations, we get b = 7.5 km/h.

Log in to practise this subject

These are sample questions with their answers. Log in to attempt them, track your accuracy, earn coins and save every session to your history.