Machine A takes 8 minutes to cut 144 pieces of lumbers. Machine B takes 15 minutes to cut 90 pieces of lumbers. Machine C takes 12 minutes to cut 132 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 → 144 pieces
1 min → 144 ÷ 8 = 18 pieces
Time taken by Machine B alone:
15 min → 90 pieces
1 min → 90 ÷ 15 = 6 pieces
Time taken by Machine C alone:
12 min → 90 pieces
1 min → 132 ÷ 12 = 11 pieces
Time taken by Machine A and Machine B together:
1 min → 18 + 6 = 24 pieces
Time taken by Machine B and Machine C together:
1 min → 6 + 11 = 17 pieces
Machine A and B are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine A and B) in 1 minute
= 24 - 17
= 7
Answer(s): (a) A, B or B, A; (b) 7