PSLE
One copier took 90 minutes while another took 120 minutes to print the same number of leaflets. The faster copier printed 12 more leaflets per minute than the slower one.

1. The slower copier completed the job at 2.13 p.m. At what time was the printing started?
2. What was the total number of leaflets printed by the two copiers?

(a)
120 min before 2.13 p.m. = 12.13 p.m.

Time that the printing started for the slower copier = 12.13 p.m.

(b)
Extra leaflets that the faster copier printed in 90 min
= 90 x 12
= 1080

Difference in the time needed to print the leaflets
= 120 - 90
= 30 min

Speed of the slower copier
= 1080 ÷ 30
= 36

Number of leaflets printed by the slower copier
= 120 x 36
= 4320

Both copiers printed the same number of leaflets.

Number of leaflets printed by the 2 copiers
= 2 x 4320
= 8640

Answer(s): (a) 12.13 p.m.; (b) 8640