PSLE
Mr Lau used two printers with different printing rates for a printing job. He started Printer B at 21 02 and started Printer C three minutes later. He stopped both copiers at 21 07. 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 B at the time Mr Lau started Printer C?
2. What was the difference in the number of pages printed by the two copiers from 21 02 to 21 07?
3. Which printer, B or C, has a faster printing rate? What is the difference in the number of pages printed by the copiers in one minute? Give your answer in this format. (Eg A, 1)

(a)
At 21 05, number of pages that Printer B printed = 168

(b)
Number of pages printed by Printer B from 21 02 to 21 07
= 280

Number of pages printed by Printer C from 21 02 to 21 07
= 120

Difference in the number of pages printed by the two copiers from 21 02 to 21 07
= 280 - 120
= 160

(c)
Printing rate of Printer B
= 280 ÷ 5
= 56

Printing rate of Printer C
= 120 ÷ 2
= 60 (Faster)

Difference in the number of pages printed by the copiers in one minute
= 60 - 56
= 4

Answer(s): (a) 168; (b) 160; (c) C, 4