P alone can do a piece of work in 12 days. P and Q can do the same work in 7 1/2 days. In how many days Q alone can do it.
Answers
Step-by-step explanation:
- P = 12 day
- P+Q = 7 1/2 = 15/2 days
for to convert the fraction into whole number ,
multiply both the days by 2 ,
P = 24 days
P+Q = 15 days
we can assume the total work by taking LCM for both the days
LCM for 24,15 = 120 work
- Capacity = work / time
we have to find capacity of P and Q ,
P's capacity = 120/24 = 5 units
P + Q capacity = 120 /15 = 8 units
P+Q = 8
Substitute P' s capacity in P+ Q
5+ Q = 8
Q = 3 UNITS
Q alone can do the total work = 120/3
= 40 days
at 1st we multiplyied both the days by 2, so now we have to divide the Q's time by 2 ,
Q = 20 days