Maths Practice Question and Answer

Q:

The average per day income of A, B and C is Rs. 450. If the average per day income of A and B be Rs. 400 and that of B and C be Rs. 430, the per day income of B is: 

2128 0

  • 1
    Rs . 300
    Correct
    Wrong
  • 2
    Rs . 310
    Correct
    Wrong
  • 3
    Rs. 415
    Correct
    Wrong
  • 4
    Rs . 425
    Correct
    Wrong
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Answer : 2. "Rs . 310 "

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Answer : 4. "12 m "

Q:

The cost price of 12 pens is equal to the selling price of 8 pens. The profit percentage is:

2128 0

  • 1
    50 %
    Correct
    Wrong
  • 2
    40 %
    Correct
    Wrong
  • 3
    55 %
    Correct
    Wrong
  • 4
    45 %
    Correct
    Wrong
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Answer : 1. "50 %"

Q:

Rashid borrowed Rs.15000 at the rate of 10% p.a. rate of compound interest, compound annually. He repaid a certain amount at the end of the first. Then he paid Rs. 12100 at the end of the 2nd year to completely discharge the loan. What amount did he repay at the end of 1st year?

2128 0

  • 1
    4500
    Correct
    Wrong
  • 2
    5500
    Correct
    Wrong
  • 3
    6500
    Correct
    Wrong
  • 4
    5800
    Correct
    Wrong
  • 5
    None of these
    Correct
    Wrong
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Answer : 2. "5500"

Q: Average age of 21 men reduces by 1 year when a man of 32 years is replaced by a child. What is the age of that child? 2127 0

  • 1
    10 years
    Correct
    Wrong
  • 2
    11 years
    Correct
    Wrong
  • 3
    9 years
    Correct
    Wrong
  • 4
    8 years
    Correct
    Wrong
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Answer : 2. "11 years"
Explanation :

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Q:

Akhil takes 30 minutes extra to cover a distance of 150 km if he drives 10 km/h slower than his usual speed. How much time will he take to drive 90 km if he drives 15 km per hours slower than his usual speed?

2127 0

  • 1
    2h 45m
    Correct
    Wrong
  • 2
    2h 30m
    Correct
    Wrong
  • 3
    2h
    Correct
    Wrong
  • 4
    2h 15m
    Correct
    Wrong
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Answer : 3. "2h "
Explanation :

Let's use the information given to calculate Akhil's usual speed first.

We know that Akhil takes 30 minutes (0.5 hours) extra to cover a distance of 150 km when he drives 10 km/h slower than his usual speed.

Let "S" be Akhil's usual speed in km/h. So, his slower speed would be (S - 10) km/h.

The time taken to cover a distance is equal to the distance divided by the speed: Time = Distance / Speed

At his usual speed, it takes him: Time at usual speed = 150 km / S hours

At the slower speed, it takes him: Time at slower speed = 150 km / (S - 10) hours

The difference in time between these two scenarios is 0.5 hours (30 minutes): Time at slower speed - Time at usual speed = 0.5 hours

Now, we can set up the equation and solve for S:

(150 km / (S - 10)) - (150 km / S) = 0.5

To solve this equation, we'll first get a common denominator: [150S - 150(S - 10)] / [S(S - 10)] = 0.5

Now, simplify and solve for S: [150S - 150S + 1500] / [S(S - 10)] = 0.5

1500 / [S(S - 10)] = 0.5

Now, cross-multiply: 2 * 1500 = S(S - 10)

3000 = S^2 - 10S

S^2 - 10S - 3000 = 0

Now, we can solve this quadratic equation for S using the quadratic formula:

S = [-(-10) ± √((-10)^2 - 4(1)(-3000))] / (2(1))

S = [10 ± √(100 + 12000)] / 2

S = [10 ± √12100] / 2

S = [10 ± 110] / 2

Now, we have two possible values for S, but we'll take the positive one because speed cannot be negative:

S = (10 + 110) / 2 = 120/2 = 60 km/h

So, Akhil's usual speed is 60 km/h.

Now, we want to find out how much time he will take to drive 90 km when he drives 15 km/h slower than his usual speed, which would be (60 - 15) = 45 km/h.

Time = Distance / Speed Time = 90 km / 45 km/h = 2 hours

Akhil will take 2 hours to drive 90 km when he drives 15 km/h slower than his usual speed.

Q: A shopkeeper earns a profit of 10% after allowing a discount of 20% on the marked price. The cost price of the article whose marked price is Rs. 880, is 2127 1

  • 1
    Rs. 704
    Correct
    Wrong
  • 2
    Rs. 640
    Correct
    Wrong
  • 3
    Rs. 774
    Correct
    Wrong
  • 4
    Rs. 680
    Correct
    Wrong
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Answer : 2. " Rs. 640"
Explanation :

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