105 people could complete a work in 36 days. But after they worked together for 7 days their employer wanted the work should be completed in a total of 28 days. How many more workers need to be employed to meet the deadline?

Let the efficiency of each worker be X. Now, the total work = 105 × X x 36. Let Y number of workers need to be employed to get the work done in 28 days. Work done in 7 days = 105 × X x 7 = 735X Remaining days = 28-7 =21 days Work done in 21 days = (105 + Y) x X × 21 According to the concept, 105 x X x 36 = 735X+ (105 + Y) × X × 21 105 x 36 = 735 + (105 + Y) x 21 3780=735 + 2205 + 21Y 21Y=840 Y = 840/21 Y = 40   40 more workers need to be employed to meet the deadline.