Answer:
option (B) 5
Explanation:
Given:
Estimated number of men required if no rain = 10
Number of days required in there is no rain = 110
Number of days with rain = 5
Number of people hired after the 61st day = 6
Therefore,
Total man-days required = 10 × 110 = 1100
Total Man-days before 61st day
= (60 days - number of days with rain ) × Initial number of men
= ( 60 - 5 ) × 10
= 550
let the number of days it rained after day 60 be 'n'
Thus,
Man-days worked after 61st day
= Total number of men after 61st day × ( 100 days - 60 days - x )
= 16 × (40 - n)
also,
Total man-days required = Total Man-days before 61st day + Man-days worked after 61st day
or
1,100 = 550 + 16 × ( 40 - n )
or
550 = 640 - 16n
or
n = 5.625
therefore,
It rained for 5 days
option (B) 5
