Sr1994 wrote:
In the initial 5 days, 30 units were completed.
It is mentioned that the rate of each employee working in the initial 5 days is 2 units per day
So, to find the total rate, let x = no: of employees working in the initial 5 days
(2*x)*5 = 30
x = 3
Total rate = 6
In the last 2 days, the employees have to complete 60 units
We don't know the new number of employees or their rate.
[6+(a*r)]*2 = 60
12+2ar = 60
2ar = 48
ar = 24
a<r, Condition mentioned in the question.
From the given values, a = 4 & r = 6 is the only option that gives a*r = 24
Answer a = 4, r = 6
I think it is worth pointing out that the rate, 2 units per day, per employee is not a vital information to arrive at the result. Let R be the total rate of work of the initial number of employees. Then R = (90 - 60)/5 = 30/5 = 6. So we can go ahead and write:
(R +ra)*2 = 60; 2, here, of course, refers to the 2 last days
(6 + ra)*2 = 60
ra = 24