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

Quantitative Aptitude

BASIC MATHS MCQs

Total Questions : 233 | Page 5 of 24 pages

Question 41. Machine P can print one lakh books in 8 hours. Machine Q can print the same number of books in 10 hours while machine R can print the same in 12 hours. All the machines started printing at 9 A.M. Machine P is stopped at 11 A.M. and the remaining two machines complete work. Approximately at what time will the printing of one lakh books be completed?

3 pm
2 pm
1:00 pm
11 am

Discuss Question

Answer: Option C. -> 1:00 pm
WORK DONE BY P IN 1 HOUR = 1/8
WORK DONE BY Q IN 1 HOUR = 1/10
WORK DONE BY R IN 1 HOUR = 1/12
WORK DONE BY P,Q AND R IN 1 HOUR = 1/8 + 1/10 + 1/12 = 37/120
WORK DONE BY Q AND R IN 1 HOUR = 1/10 + 1/12 = 22/120 = 11/60
FROM 9 AM TO 11 AM, ALL THE MACHINES WERE OPERATING.
IE, THEY ALL OPERATED FOR 2 HOURS AND WORK COMPLETED = 2 × (37/120) = 37/60
PENDING WORK = 1- 37/60 = 23/60
HOURS TAKEN BY Q AN R TO COMPLETE THE PENDING WORK = (23/60) / (11/60) = 23/11
WHICH IS APPROXIMATELY EQUAL TO 2
HENCE THE WORK WILL BE COMPLETED APPROXIMATELY 2 HOURS AFTER 11 AM ; IE AROUND 1 PM

Question 42. Farjan and Kashif can complete a task in 30 days. Farjan leaves after 20 days and Kashif alone completes it in another 25 days. How many days does Farjan alone take to complete the entire task?

Discuss Question

Answer: Option A. -> 50
PART OF WORK COMPLETED BY FARJAN AND KASHIF IN A DAY
= 1/30 PART OF WORK COMPLETED BY THEM IN 20 DAYS
= 20/30 = 2/3 1/3 OF THE WORK IS REMAINING. KASHIF COMPLETES 1/3RD OF THE WORK IN 25 DAYS. PART OF WORK COMPLETED BY HIM IN A DAY
= (1/3)÷25
= 1/75 (1/D)+(1/V) = 1/30 (1/D) = (1/30)-(1/75) = 1/50 FARJAN CAN COMPLETE IT IN 50 DAYS.

Question 43. Two pipes P and Q can fill a cistern in 12 min. and 15 min. respectively but a third pipe ‘R’ can empty the full tank in 6 min. P and Q are kept open for 5 min. in the beginning and then ‘R’ is also opened. In what time is the cistern emptied ?

30 min
35 min
40 min
45 min

Discuss Question

Answer: Option D. -> 45 min
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 44. P is able to do a piece of work in 15 days and Q can do the same work in 20 days. If they can work together for 4 days, what is the fraction of work left?

8/15
7/15
11/15
2/11

Discuss Question

Answer: Option A. -> 8/15
AMOUNT OF WORK P CAN DO IN 1 DAY = 1/15
AMOUNT OF WORK Q CAN DO IN 1 DAY = 1/20
AMOUNT OF WORK P AND Q CAN DO IN 1 DAY = 1/15 + 1/20 = 7/60
AMOUNT OF WORK P AND Q CAN TOGETHER DO IN 4 DAYS = 4 × (7/60) = 7/15
FRACTION OF WORK LEFT = 1 – 7/15= 8/15

Question 45. A and B can together do a piece of work in 15 days. B alone can do it in 20 days. In how many days can A alone do it ?

40 days
50 days
60 days
70 days

Discuss Question

Answer: Option C. -> 60 days
(A+B)’S 1 DAY’S WORK = [1/15−1/20]=1/60
A ALONE CAN FINISH IT IN 60 DAYS

Question 46. A completes 80% of a work in 20 days. Then B also joins and A and B together finish the remaining work in 3 days. How long does it need for B if he alone completes the work?

37 ½ days
22 days
31 days
22 days

Discuss Question

Answer: Option A. -> 37 ½ days
WORK DONE BY A IN 20 DAYS = 80/100 = 8/10 = 4/5
WORK DONE BY A IN 1 DAY = (4/5) / 20 = 4/100 = 1/25 — (1)
WORK DONE BY A AND B IN 3 DAYS = 20/100 = 1/5 (BECAUSE REMAINING 20% IS DONE IN 3 DAYS BY A AND B)
WORK DONE BY A AND B IN 1 DAY = 1/15 —(2)
WORK DONE BY B IN 1 DAY = 1/15 – 1/25 = 2/75
=> B CAN COMPLETE THE WORK IN 75/2 DAYS = 37 ½ DAYS

Question 47. Kamal will complete work in 20 days. If Suresh is 25% more efficient than Kamal, he can complete the work in________days.

Discuss Question

Answer: Option B. -> 16
WORK DONE BY KAMAL IN 1 DAY = 1/20
WORK DONE BY SURESH IN 1 DAY = (1/20) × (125/100) = 5/80 = 1/16
=> SURESH CAN COMPLETE THE WORK IN 16 DAYS

Question 48. P can do a work in 24 days. Q can do the same work in 9 days and R can do the same in 12 days. Q and R start the work and leave after 3 days. P finishes the remaining work in_________days.

Discuss Question

Answer: Option A. -> 10
WORK DONE BY P IN 1 DAY = 1/24
WORK DONE BY Q IN 1 DAY = 1/9
WORK DONE BY R IN 1 DAY = 1/12
WORK DONE BY Q AND R IN 1 DAY = 1/9 + 1/12 = 7/36
WORK DONE BY Q AND R IN 3 DAYS = 3×7/36 = 7/12
REMAINING WORK = 1 – 7/12 = 5/12
NUMBER OF DAYS IN WHICH P CAN FINISH THE REMAINING WORK = (5/12) / (1/24) = 10

Question 49. 12 buckets of water fill a tank when the capacity of each bucket is 13.5 litres. How many buckets will be needed to fill the same tank, if the capacity of each bucket is 9 litres?

Discuss Question

Answer: Option D. -> 18
CAPACITY OF THE TANK = (12×13.5)=162 LITRES
CAPACITY OF EACH BUCKET = 9 LITRES.
NUMBER OF BUCKETS NEEDED = 162/9=18

Question 50. Jameel can complete a task in 15 hours and Nasir can complete the same task in 12 hours. Jameel starts the task at 9:00 am and stops working at 2:00pm. Nasir starts working on the task at 4:00 pm. At what time is the task completed?

12:00 pm
2:00 am
12:00 am
10:00 pm

Discuss Question

Answer: Option C. -> 12:00 am
JAMEEL WORKS FOR 5 HOURS. SO HE COMPLETES 5/15 = 1/3 OF THE TASK NASIR HAS TO COMPLETE 2/3RD OF THE TASK 12*2/3 = 8 HOURS ARE NEEDED. HE COMPLETES THE TASK AT 12:00 AM.