Machine A takes 8 minutes to cut 80 pieces of lumbers. Machine B takes 12 minutes to cut 84 pieces of lumbers. Machine C takes 11 minutes to cut 154 pieces of lumber.
- Which is the faster combination, A and B or B and C? (Eg A, B)
- In 1 minute, how many more pieces of lumbers can be cut by the faster combination compared to the other combination?
(a)
Time taken by Machine A alone:
8 min → 80 pieces
1 min → 80 ÷ 8 = 10 pieces
Time taken by Machine B alone:
12 min → 84 pieces
1 min → 84 ÷ 12 = 7 pieces
Time taken by Machine C alone:
11 min → 84 pieces
1 min → 154 ÷ 11 = 14 pieces
Time taken by Machine A and Machine B together:
1 min → 10 + 7 = 17 pieces
Time taken by Machine B and Machine C together:
1 min → 7 + 14 = 21 pieces
Machine B and C are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine B and C) in 1 minute
= 21 - 17
= 4
Answer(s): (a) B, C or C, B; (b) 4