A new photocopier can make 72 copies in 2 min. When an older photocopier is operational, the two photocopiers together can make 72 copies in 1.5 min. How long would it take the older photocopier to make 72 copies working alone?

Question

raden · Answer

t1 * t2 / (t1 + t2) = 1.5
plug t1 = 2 to equation above to get t2 :

2t2/(2+t2) = 1.5
solve for t2 = ...

anonymous · Answer

what is t supposed to stand for?

raden · Answer

t1 for the time if the new fotocopier works alone and t2 for the old fotocopier

raden · Answer

got it ?