Question

6 men can complete theelectric fitting in a building in 7 days. How many days will it take if 21 men do the job?

Answer 1

6 men can complete the work in =7 days

1 man will complete the same work in = $7\times 6$ days

(Less men, more days)

$\therefore 21$ men will finish the work in $=\frac{7\times 6}{21}$ days

(More men, less days)

=2 days