Question

A man and a boy can complete digging in
40 days. The ratio of their speed of digging
is 8 : 5. How many days the boys alone will
take to do this work?
B. 52 days
D. 80 days
A 68 days
C. 104 days

Answer 1

Answer:

C. 103 days

Step-by-step explanation:

Ratio of digging speeds of man and boy = 8 : 5

Ratio of times taken by man and boy = 5 : 8

Suppose the man takes 5x days while the takes 8x

Then,

⇒15x+18x=140⇒1340x=140⇒x=13

Hence, time taken by the boy to complete the work alone

= (8×13)days = 104 days