Assuming by "more efficient" you mean that he has a better rate.
Let the job to be done be 1 units of work
Let A's rate be 1/30
then B's rate is 1.25(1/30) = 1.25/30 = 1/24
C's rare is 1.2(1.25/30) = 1/20
combined rate of A and B = 1/30 + 1/24 = 3/40
working for 10 days, work done is 10(3/40) = 3/4
work remaining to be done = 1 - 3/4 = 1/3
time taken by C = x
x = (1/3) / (1/20) = 20/3 days or 6 2/3 days
A can do a certain work in 30 days. B is 25% more efficient than A, and C is 20% more efficient than B. A and B work together for 10 days. C alone completes the remaining work in x days. the value of x is
3 answers
It should be 1/4 รท 1/20 ??????
Of course, it was a carry-over-typo
Sorry about that.
Sorry about that.