Say, each worker does "p" units of work in a day.
Work = 10 x 112 x p= 1120p
In 61 days, ideally, 10 x 61 x p = 610p amount of work should have happened.
But there were 5 power outages. 1 power outage means 1 day lost.
So,
Actual days of work = 61-5 = 56.
So,
Actual work done in 61 days = 10 x 56 x p = 560p
Remaining work as of 61 days = 1120p - 560p = 560p
From day 62 onwards, there are 10+4 = 14 workers.
Ideally, how long would the remaining work (560p) take for these 14 workers?
14 x (d) x p = 560p
d = 40
Ideally, the remaining work should have taken 40 days. This brings us to a total of 61 + 40 = 101 days of total work.
But the actual number of days taken is 104.
This means that 104 - 101 = 3 days were again lost due to power outages.
The overall number of power outages = 5 (from day 1 to day 62) + 3 (from day 62 till the end) = 8 days. Choice E.
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Harsha