we know: the comparision is of apple with apple and orange with orange, right.

so to have correct comparsion, we need to find the rate of work done by B in 1 minuet with the same of the A in the same minuet. so find the rate of work/minuet for both, A and B.

so find the rate of work A and B can do in 1 minuet.

lets suppose the whole job = x.

A can do the whole job (x) in 60 minuets.

or, it takes 60 minuets for A to complete the job (x).

if so, then in 1 inuet A can do 1/60 part of the whole job (x).

Same to B:

B can do the same job (x) in 40 minuets.

B can do 1/40 job (x) in 1 minuet.

here, we know that B does more work in 1 inuet than A does. So now get the excess work done by B, i.e. the difference between the work done by A and B in 1 minuet:

= {(1/40)-(1/60)} of the whole job (x)

= 1/120 of the whole job (x)

as given, B can paint 5 more pages than A in 1 minuet and we have from the above solution that B can do (1/120) (x) more work in 1 minuet than A. so,

5 pages = (1/120) x

x = 600 pages.

hope helpssssss................

fresinha12 wrote:

HIMA, could you explain this in more detail, why are you subtracting As rate from B?

so, B can do (1/40)-(1/60) or 1/120 job in 1 minuet

B can do 1/120 of whole job, which is 5 more pages paint, in 1 minuet

so the whole job contain 600 pages.

HIMALAYA wrote:

A can do the same job in 60 minuets.

A can do 1/60 job in 1 minuet.

B can do the same job in 40 minuets.

B can do 1/40 job in 1 minuet.

so, B can do (1/40)-(1/60) or 1/120 job in 1 minuet

B can do 1/120 of whole job, which is 5 more pages paint, in 1 minuet

so the whole job contain 600 pages.

Verification:

A can paint 10 (600/60) pages in 1 minuet.

B can paint 15 (600/40) pages in 1 minuet.

so the difference between B's work and A's work in 1 minuet is 5 (15-10) pages.