Efficiency of Rashid and Danish are in the ratio 5:8. If Danish takes 51 days less than Rashid to complete the work, find the time taken by Rashid to complete the work?
A.
85 days
B.
126 days
C.
118 days
D.
136 days
Answer: Option D
Explanation:
Time taken is inversely proportional to their efficiency. So, time taken is in the ratio 8:5. Time taken by Rashid to finish the work = 8x Time taken by Danish to finish the work = 5x 8x-5x=51 3x=51 x=17 8x=136
If daily wages of a man is double to that of a woman, how many men should work for 25 days to earn Rs.14400? Given that wages for 40 women for 30 days are Rs.21600?
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?
A.
8/15
B.
7/15
C.
11/15
D.
2/11
Answer: Option A
Explanation:
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
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 ?
