Two men and 7 children complete a certain piece of work in 4 days while 4 men and 4 children complete the same work in only 3 days. The number of days required by 1 man to complete the work is

Explanation:

According to question,

(2M +7C)’s 1 day work = 1\4

It means that 1 work will be finished by (8M + 28C)

Again, (4M + 4C)’s 1 day’s work = 1\3

or 1 work will be completed by 12M + 12C

∴8M + 28C = 12M + 12C

=> M = 4C

∴ 4M + 4C = 5M

Since, 5 M complete a work in 3 days. Then, 1 M will complete it in 5 days.