Question

30 men can do a work in 30 days and 40 women can do the same work in 40 days. if they started working together, how many more men required completing the work in 10 days?

Answer 1

30 men --------- 30 days

1 man --------- 900 days

x men --------- 900/x days

also ,

40 women --------- 40 days


now 30 men takes 30 days

so in one day they complete 1/30 of work

40 women takes 40 days

so in one day they complete 1/40 of work

both together completes the work in one day = 1/30 + 1/40

let x more men required to complete the work in 10 days

so x men perform x/900 work in a day

so

1/30 + 1/40 + x/900 = 1/10


1/3 + 1/4 + x/90 = 1/1

7/12+x/90 = 1

630 + 12x = 1080

12x = 1080 - 630

12x = 450

x = 450 /12

x = 37.5

so nearabout 38 more men required to complete the work in 10 days

x = 37