PSLE
Mr Loh used two printers with different printing rates for a printing job. He started Printer C at 11 35 and started Printer D one minute later. He stopped both printers at 11 40. 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 C at the time Mr Loh started Printer D?
2. What was the difference in the number of pages printed by the two printers from 11 35 to 11 40?
3. Which printer, C or D, 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 11 36, number of pages that Printer C printed = 80

(b)
Number of pages printed by Printer C from 11 35 to 11 40
= 400

Number of pages printed by Printer D from 11 35 to 11 40
= 850

Difference in the number of pages printed by the two printers from 11 35 to 11 40
= 850 - 400
= 450

(c)
Printing rate of Printer C
= 400 ÷ 5
= 80 (Slower)

Printing rate of Printer D
= 850 ÷ 4
= 212.5 (Faster)

Difference in the number of pages printed by the printers in one minute
= 212.5 - 80
= 132.5

Answer(s): (a) 80; (b) 450; (c) C, 132.5