Question

George and mark can paint 720 boxes in 20 days. Mark and harry in 24 days and harry and george in 15 days. George works for 4 days, mark for 8 days and harry for 8days. The total number of boxes painted by them is a)252

Answer 1

Answer:

Total number of boxes painted by George, Mark and Harry = 348

Step-by-step explanation:

Let

The no. of boxes, George paints in 1 day = x

The no. of boxes, Mark paints in 1 day = y

The no. of boxes, Harry paints in 1 day = z

In 20 days, George and Mark can paint = 720 boxes

∴ 20x + 20y = 720

or, x + y = 36         ................ (1)

Similarly

24y + 24z = 720

or, y + z = 30         ................ (2)

And

15x + 15z = 720

or, x + z = 48         ................ (3)

Adding eq (1) , (2) and (3)

2(x + y + z) = 36 + 30 +48

or x + y + z = 57          ................ (4)

Subtracting eq (1) from eq (4)

we get

z = 21

Similarly, by subtracting eq (2) from eq (4) we get

x = 27

And by subtracting eq (3) from eq (4) we get

y = 9

No. of boxes painted by George, Mark and Harry

= 4 x 27 + 8 x 9 + 8 x 21

= 348