8 children and 12 men complete a certain piece of work in 9 days. If each child takes twice the time taken by a man to finish the work, in how many days will 12 men finish the same work ?
A.
6 days
B.
8 days
C.
10 days
D.
12 days
Answer: Option D
Explanation:
2 children = 1 man (8 children + 12 men ) = 16 men Now, less men, more days 12 : 16 : 9 : x x = 16×9/12=12 days
15 men can build a 500m long wall in 30 days. In how many days can 30 men build a 1.2 km long wall?
A.
24 days
B.
48 days
C.
40 days
D.
36 days
Answer: Option D
Explanation:
No. of days is directly proportional to the length of the wall and inversely proportional to the number of men No. of days = (1200/500)*(15/30)*30 = 36 days
If 28 men can finish a work in 15 days, 21 men can finish the same work in?
A.
12 days
B.
14 days
C.
18 days
D.
20 days
Answer: Option D
Explanation:
Time and Men are inversely proportional. Time taken by 28 men to finish the work = 15 days Time taken by a man to finish the work = 15*28 days Time taken by 21 men = (15*28)/21 = 20 days
P,Q and R together earn Rs.1620 in 9 days. P and R can earn Rs.600 in 5 days. Q and R in 7 days can earn Rs.910. How much amount does R can earn per day?
A.
Rs.40
B.
Rs.70
C.
Rs.80
D.
Rs.95
Answer: Option B
Explanation:
Amount Earned by P,Q and R in 1 day = 1620/9 = 180 —(1) Amount Earned by P and R in 1 day = 600/5 = 120 —(2) Amount Earned by Q and R in 1 day = 910/7 = 130 —(3) (2)+(3)-(1) => Amount Earned by P , Q and 2R in 1 day – Amount Earned by P,Q and R in 1 day = 120+130-180 = 70 =>Amount Earned by R in 1 day = 70
P and Q can complete a work in 20 days and 12 days respectively. P alone started the work and Q joined him after 4 days till the completion of the work. How long did the work last?
A.
5 days
B.
10 days
C.
15 days
D.
20 days
Answer: Option C
Explanation:
Work done by P in 1 day = 1/20 Work done by Q in 1 day = 1/12 Work done by P in 4 days = 4 × (1/20) = 1/5 Remaining work = 1 – 1/5 = 4/5 Work done by P and Q in 1 day = 1/20 + 1/12 = 8/60 = 2/15 Number of days P and Q take to complete the remaining work = (4/5) / (2/15) = 6 Total days = 4 + 6 = 10
