PSLE
Mr Loo used two printers with different printing rates for a printing job. He started Printer W at 20 51 and started Printer X one minute later. He stopped both printers at 20 56. The graphs show the total number of pages printed by each printer from the start of printing.

1. How many pages had been printed by Printer W at the time Mr Loo started Printer X?
2. What was the difference in the number of pages printed by the two printers from 20 51 to 20 56?
3. Which printer, W or X, has a slower printing rate? What is the difference in the number of pages printed by the printers in one minute? Give your answer in this format. (Eg A, 1)

(a)
At 20 52, number of pages that Printer W printed = 30

(b)
Number of pages printed by Printer W from 20 51 to 20 56
= 150

Number of pages printed by Printer X from 20 51 to 20 56
= 270

Difference in the number of pages printed by the two printers from 20 51 to 20 56
= 270 - 150
= 120

(c)
Printing rate of Printer W
= 150 ÷ 5
= 30 (Slower)

Printing rate of Printer X
= 270 ÷ 4
= 67.5 (Faster)

Difference in the number of pages printed by the printers in one minute
= 67.5 - 30
= 37.5

Answer(s): (a) 30; (b) 120; (c) W, 37.5