When both printers S and T are used, a collection of books can be printed in 6 hours. While printing, Printer S broke down. As a result, it took 6
23 hours to complete printing. If it would take Printer T 10 hours to print the collection alone,
- How long would it take to print the collection of books using only Printer S? Express your answer in hours.
- How long was Printer S used before it broke down? Express your answer in hours.
(a)
Time taken by Printer S and T:
6 h → 1 collection of books
1 h → 1 ÷ 6 =
16 collection of books
Time taken by only Printer T:
10 h → 1 collection of books
1 h → 1 ÷ 10 =
110 collection of books
Time taken by only Printer S:
1 h →
16 -
110 =
115 collection of books
1 collection of books → 1 ÷
115 = 1 x 15 = 15 h
(b)
Time taken by only Printer T:
6
23 h → 6
23 x
110 =
23 collection of books
Fraction of the collection of books to be done by Printer S
= 1 -
23=
13 Time taken by Printer S before it broke down:
13 collection of books →
13 ÷
16 =
13 x
61 = 2 h
Answer(s): (a) 15 h; (b) 2 h