Time and work related

guerrero wrote:A can do a piece of work in 10 days, B in 15 days. They work for 5 days. The rest of work finished by C in 2 days. If they get $1500 for the whole work, the daily wages of B and C are how much ?

a)150
b)225
c)250
d)300
e)450
[spoiler]

OA B[/spoiler]

Let the job = 30 units.

Since A can complete the job in 10 days, A's rate = w/t = 30/10 = 3 units per day.
Since B can complete the job in 15 days, B's rate = w/t = 30/15 = 2 units per day.

Work produced by A in 5 days = r*t = 3*5 = 15 units.
Work produced by B in 5 days = r*t = 2*5 = 10 units.
The remaining work is produced by C:
30-15-10 = 5 units.

Since B produces 10 of the 30 units, B earns 10/30 = 1/3 of the total amount paid:
(1/3)1500 = 500.
Since B works for 5 days, B's daily payrate = 500/5 = $100 per day.

Since C produces 5 of the 30 units, C earns 5/30 = 1/6 of the total amount paid:
(1/6)1500 = 250.
Since C works for 2 days, C's daily payrate = 250/2 = $125 per day.

Sum of the two daily payrates = 100+125 = 225.

The correct answer is B.

Rate of work done by A in one day 10%
Rate of work done by B in one day 6.67%
Percentage work done together in 1 day 16.67%
Total work done by them in 5 days 16.67 * 5= 83.35%
Work left for C 100-83.35= 16.65%
Total percentage work done by A= 50%
Total percentage work done by B = 6.67*5= 33.35 %
Total percentage work done by C = 16.65%
So ratio of wages shall be in the ratio of the total work done by them 3:2:1
Total of B and C shall be 500 and 250
Daily shall be 500/5 + 250/2 = 100+125= 225 answer