Mathematics Quiz for Juniors

Published by Rahul Aggrawal on

Mathematics Quiz for Juniors

1 – A man moves upstream in 6 hours in a boat at a speed of 20km/h. Then he rows down in 3 hours. What is the rate of flow of the stream?

  1. 20 km/h

  2. 12 km/h

  3. 15 km/h

  4. 8 km/h

  5. 10km/h

2 – 300 apples are equally distributed amongst a certain number of students. If there were 10 students more each will get alone one apple less. Find total number of students.

  1. 60

  2. 50

  3. 70

  4. 100

  5. None of these

3 – If a number multiplied by 25% of itself gives a number which is 200% more than the number, then the number is

  1. 12

  2. 16

  3. 20

  4. 24

4 – A bus can go from A to B via two routes 1 and 2 with speed kept the same. It takes 40 % more time in route 1 than in route 2. If distance of route 2 is 150 km and total fuel used in both the routes is 84 litres. Then find the difference of oil consumed in both the routes.

  1. 12.5 litre

  2. 13 litre

  3. 14 litre

  4. 11.5 litre

  5. 14.5 litre

5 – Chords AB and CD of a circle intersect externally at P. If AB = 6 cm, CD = 3 cm and PD = 5 cm, then the length of PB is

 

  1. 5 cm

  2. 7.35 cm

  3. 6 cm

  4. 4 cm

6 – A pipe can filled a tank in 6 hrs. After half tank is filled 3 more similar pipes are opened. What is total time taken to be filled.

  1. 3 hour 48 minutes

  2. 3 hour 48 minutes

  3. 3 hour 30 minutes

  4. 4 hour 40 minutes

7 – A shopkeeper is selling sugar at 15% profit but with 25% false weight. Find the total profit percentage.

  1. 33.33

  2. 53.33

  3. 45.75

  4. 60.25

8 – What is the ratio of distance travelled by a car going at 50kmph for 8 hours to a bike going at 37.5kmph for 4 hours to a scooter going at 22.5kmph for 6 hours?

  1. 80:30:25

  2. 80:31:27

  3. 80:31:29

  4. 80:30:27

9 – If x : y be the ratio of two whole numbers and z be their HCF, then the LCM of those two numbers is

  1. xy

  2. (xz/y)

  3. (xy/z)

  4. xyz

10) – If 7A = 5B = 2C; find A : B : C.

  1. 35:14:10

  2. 14:10:35

  3. 2:5:7

  4. 10:14:35

1 – Solution : – e

As the man moves upstream in 6 hours at a speed of 20km/h, the length of the stream = Speed × Time = 20 × 6 = 120 km
So, speed of the boat downstream = Distance/Time = 120/3 = 40km/h
So, let the speed of the boat in still water be x km/h and the rate of flow of the stream be y km/h.
For upstream, x – y = 20
For, downstream, x + y = 40
On solving the above two equations, we get y = 10km/h.
So, rate of flow of the stream is 10km/h.

2 – Solution : – b

Let total number of student = x
According to question.
From option x = 50 satisfy the given equation.

3 – Solution : a

Let the number be x. Remember the given number is 200% more than the original so, new number will be 300% of the original one.

4 – Solution : c

As the speed of the bus is same so distance of route 1 = 40 % more than route 2.
Distance of route 1=1.4*150=210 km
As the fuels used in routes is directly proportional to the distance travel in the routes.
The ratio of fuel used in different routes= ratio of the difference of two routes.
Ratio of fuel used in different routes=210:150=7:5
Let, fuel in route 1 = 7x
Fuel in route 2 = 5x
Total fuel = 84
 12x=84
 x=7
Fuel used in route 1 = 49 litre
Fuel used in route 2 = 35 litre
Required difference = 49-35=14 litre

5 – b

6 – Solution : – b

A can fill it in 6 hours than we consider 6 is total work and A’s 1 hour work =1
ATQ. Half tank is filled by A
=3 hours
Remaining 3 by 4 pipes, so 3/4 more time
Total time = 3 hours + 3/4 hours
=3 hours 45 minutes

7 – Solution : – b

Let the cost price 1 kg sugar be Rs. x.
A shopkeeper is selling sugar at 15% profit but with 25% false weight.
That means, he is selling 750gm instead of 1000gm.
So, the cost price of 750gm sugar = Rs. x × (750/1000) = Rs. 3x/4
But he is taking the price of 1 kg sugar with 15% profit.
So, the selling price of 1 kg = Rs. x × (115/100) = Rs. 23x/20
Then, the profit = Rs. (23x/20) – (3x/4) = Rs. 2x/5
 The profit percentage = [(2x/5)/(3x/4)] × 100 = 53.33.

8 – Solution : d

Distance travelled by the car = 50 * 8 = 400km
Distance travelled by the bike = 37.5 * 4 = 150km
Distance travelled by the scooter = 22.5 * 6 = 135km
Ratio of distance travelled = 400:150:135 = 80:30:27

9 – Solution : d

First no. x Second no. = L.C.M. x H.C.F.
So, L.C.M. = zxy

10 – Solution : – d

Given: 7A = 5B = 2C. Therefore,
A/B = 5/7 and B/C = 2/5
Hence A/B = 10/14 and B/C = 14/35
Therefore,
A : B : C = 10 : 14 : 35


Rahul Aggrawal

I am a teacher and a theoretical physicist. Physics gives me pleasure and teaching physics gives me stable happiness. For More info visit www.rahulaggrawalphysics.blogspot.com

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