15 men work 8 hours per day to complete the work in 10 days . to complete the same work in 8 days , working 15 hours a day , the number of men required ?
"that is , 1 work done = 15 × 8 × 10 then , 12 8 × 10 = ? × 15 × 8 ? ( i . e . no . of men required ) = 15 × 8 × 10 / 15 × 8 = 10 days a )"
divide(multiply(multiply(15, 10), 8), multiply(8, 15))