Basic Maths(Quantitative Aptitude ) Questions and answers for exam Preparation

Quantitative Aptitude

BASIC MATHS MCQs

Total Questions : 233 | Page 6 of 24 pages

Question 51. A leak in the lower portion of a tank can empty the full tank in 9 hrs. An inlet pipe fills water at the rtae of 10 lit. a minute. When the tank is full, the inlet is opened and due to leak, the tank is empty in 16 hrs. How many litres does the cistern hold ?

12,342 litres.
12,444 litres
12,566 litres.
None of thes

Discuss Question

Answer: Option A. -> 12,342 litres.
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 52. A alone can finish a work in X days. B alone can finish the same work in X+5 days. Together, they take 6 days to complete the work. Find X

Discuss Question

Answer: Option C. -> 10
PART OF WORK COMPLETED BY A IN A DAY = 1/X PART OF WORK COMPLETED BY B IN A DAY
= 1/(X+5) (1/X)+(1/(X+5)) = 1/6 (2X+5)/(X²+5X) = 1/6 X²+5X = 6(2X+5) X²-7X-30=0 SOLVING, X=10

Question 53. P can do a work in the same time in which Q and R together can do it. If P and Q work together, the work can be completed in 10 days. R alone needs 50 days to complete the same work. then Q alone can do it in__________?

30 days
25 days
20 days
15 days

Discuss Question

Answer: Option B. -> 25 days
WORK DONE BY P AND Q IN 1 DAY = 1/10
WORK DONE BY R IN 1 DAY = 1/50
WORK DONE BY P, Q AND R IN 1 DAY = 1/10 + 1/50 = 6/50
BUT WORK DONE BY P IN 1 DAY = WORK DONE BY Q AND R IN 1 DAY . HENCE THE ABOVE EQUATION CAN BE WRITTEN AS
WORK DONE BY P IN 1 DAY × 2 = 6/50
=> WORK DONE BY P IN 1 DAY = 3/50
=> WORK DONE BY Q AND R IN 1 DAY = 3/50
HENCE WORK DONE BY Q IN 1 DAY = 3/50 – 1/50 = 2/50 = 1/25
SO Q ALONE CAN DO THE WORK IN 25 DAYS

Question 54. 10 men can complete a work in 7 days. But 10 women need 14 days to complete the same work. How many days will 5 men and 10 women need to complete the work?

Discuss Question

Answer: Option A. -> 7
WORK DONE BY 10 MEN IN 1 DAY = 1/7
WORK DONE BY 1 MAN IN 1 DAY = (1/7)/10 = 1/70
WORK DONE BY 10 WOMEN IN 1 DAY = 1/14
WORK DONE BY 1 WOMAN IN 1 DAY = 1/140
WORK DONE BY 5 MEN AND 10 WOMEN IN 1 DAY = 5 × (1/70) + 10 × (1/140)
= 5/70 + 10/140 = 1/7
=> 5 MEN AND 10 WOMEN CAN COMPLETE THE WORK IN 7 DAYS

Question 55. P and Q need 8 days to complete a work. Q and R need 12 days to complete the same work. But P, Q and R together can finish it in 6 days. How many days will be needed if P and R together do it?

Discuss Question

Answer: Option B. -> 8
LET WORK DONE BY P IN 1 DAY = P
WORK DONE BY Q IN 1 DAY =Q
WORK DONE BY R IN 1 DAY = R
P + Q = 1/8 —(1)
Q + R= 1/12 —(2)
P+ Q+ R = 1/6 —(3)
(3) – (2) => P = 1/6 – 1/12 = 1/12
(3) – (1) => R = 1/6 – 1/8 = 1/24
P + R = 1/12 + 1/24 = 3/24 = 1/8
=> P AND R WILL FINISH THE WORK IN 8 DAYS

Question 56. Running at the same constant rate, 6 identical machines can produce a total of 270 bottles per minute. At this rate, how many bottles could 10 such machines produce in 4 minutes?

2700
1080
450
1800

Discuss Question

Answer: Option D. -> 1800
NUMBER OF BOTTLES PRODUCED BY 1 MACHINE IN A MINUTE
= 270/6 NUMBER OF BOTTLES PRODUCED BY 10 MACHINES IN 4 MINUTES
= (270/6)*10*4 = 1800

Question 57. A can do (1/3) of a work in 5 days and B can do (2/5) of the work in 10 days. In how many days both A and B together can do the work ?

75/8 days
44/6 days
48/5 days
None of these

Discuss Question

Answer: Option A. -> 75/8 days
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 58. A leak in the bottom of a tank can empty the full tank in 6 hrs. An inlet pipe fills water at the rate of 4 lit. a minute. When the tank is full, the inlet is opened and due to the leak, the tank is empty in 8 hrs. The capacity of the tank in liters is_________?

5,750 litres
5,760 litres
6,890 litres
None of these

Discuss Question

Answer: Option B. -> 5,760 litres
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 59. A tap can fill a tank in 32 min. and another can empty it in 16 min. If the tank is already half full and both the tanks are opened together, the tank will be_________?

12 min
14 min
16 min
20 min

Discuss Question

Answer: Option C. -> 16 min
IN THIS PROBLEM, RATE OF WATER PIPE (WASTE) IS MORE, THE TANK WILL BE EMPTIED WHEN THE PIPES ARE OPENED.
WORK DONE IN TOTAL EMPTYING IN 1 MIN.
=1/16−1/32=1/32
NOW, FULL TANK WILL BE EMPTIED BY THEM IN 32 MINUTES.
HALF FULL TANK WILL BE EMPTIED IN 16 MINUTES.

Question 60. A and B can do a piece of work in 12 days; B and C in 15 days; C and A in 20 days. A alone can do the work in__________?