Machine A takes 9 minutes to cut 171 pieces of lumbers. Machine B takes 20 minutes to cut 160 pieces of lumbers. Machine C takes 12 minutes to cut 156 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:
9 min → 171 pieces
1 min → 171 ÷ 9 = 19 pieces
Time taken by Machine B alone:
20 min → 160 pieces
1 min → 160 ÷ 20 = 8 pieces
Time taken by Machine C alone:
12 min → 160 pieces
1 min → 156 ÷ 12 = 13 pieces
Time taken by Machine A and Machine B together:
1 min → 19 + 8 = 27 pieces
Time taken by Machine B and Machine C together:
1 min → 8 + 13 = 21 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
= 27 - 21
= 6
Answer(s): (a) A, B or B, A; (b) 6