1.A and B can do a work in 12 days. B and C in 15 days. C and A in 20 days. If A, B and C work together, they will complete the work in :
(1) 5 days
(2) 7 5/6 days
(3) 10 days
(4) 15 2/3
2.Two pipes A and B can fill a tank in 20 minutes and 30 minutes respectively, If both pipes are opened together, the time taken to fill the tank is :
(1) 50 minutes
(2) 12 minutes
(3) 25 minutes
(4) 15 minutes
3.If 6 men and 8 boys can do a piece of work in 10 days and 26 men and 48 boys can do the same in 2 days, the time taken by 15 men and 20 boys to do the same type of work will be :
(1) 5 days
(2) 4 days
(3) 6 days
(4) 7 days
4.If a man walks 20 km at 5 km/hr, he will be late by 40 minutes. If he walks at 8 km per hr, how early from the fixed time will he reach?
(1) 15 minutes
(2) 25 minutes
(3) 50 minutes
(4) 1 1/2 hours
5.A boy rides his bicycle 10 km at an average speed of 12 km per hr and again travels 12 km at an average speed of 10 km per hr his average speed of the entire trip is approximately:
(1) 10.4 km/hr
(2) 10.8 km/hr
(3) 11.0 km/hr
(4) 12.2 km/hr
6.The distance between two cities A and B is 330 km. A train starts from A at 8 a.m. and travels towards B at 60 km/hr Another train starts from B at 9 a.m. and travels towards A at 75 km/hr At what time do they meet?
(1) 10 a.m.
(2) 10 : 30 a.m.
(3) 11 : 00 a.m.
(4) 11 : 30 a.m.
7.The square root of a positive number less than 100 lies between:
(1) 0 and 1000
(2) 0 and 10
(3) – 10 and 10
(4) – 100 and 100
8.The LCM of two numbers is 864 and their HCF is 144. If one of the numbers is 288, the other number is :
(1) 576
(2) 1296
(3) 432
(4) 144
9.A boy was asked to multiply a certain number by 50. He multiplied it by 30 and got his answer less than the correct one by 400. The number to be multiplied was :
(1) 10
(2) 20
(3) 30
(4) 40
10.In a class 3/5 of the students are girls and rest are boys. If 2/9 of the girls and 1/4 of the boys are absent. What part of the total number of students are present?
(1) 23/30
(2) 23/36
(3) 18/49
(4) 17/25
Answers and Solution:
1.(3)
2.(2).
Required time = 1/(1/20+1/30)
= 1/((3+2)/60) = 60/5 = 12 Minute
3.(2) According to question :-
(6m + 8B)×10=(26m + 48B) ×2
∴ 60m + 80B = 52m + 96 B
or, 1 M = 2 B
∴ 15 M + 20 B = (30 + 20)B
= 50 boys and 6m + 8B = (12 + 8) boys = 20 boys
20 boys can finish the work in 10 days
∴ 50 boys can finish the work = (20×10)/50 = 4dasy.
4.(3) Time taken to cover 20 km at speed 5 km/hr
= 4 hours
∴ Fixed time = 4 hour – 40 minutes = 3 hour 20 min
Time taken to cover 20 km at the speed 8 km/hr =20/8
= 2 hours 30 minute
∴ Required time = 3 hours 20 minutes – 2 hr 30 min
= 50 minutes
5.(2)
6.(3)
7.(2)
8.(3)Required Number = (864×144)/288=432
9.(2)Let the required number be x
∴ According to question
50 x – 30x = 400
20 x = 400
∴ x = 20
10.(1)
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