Machine B takes 5 minutes to cut 65 pieces of lumbers. Machine C takes 11 minutes to cut 132 pieces of lumbers. Machine D takes 9 minutes to cut 99 pieces of lumber.
- Which is the faster combination, B and C or C and D? (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 B alone:
5 min → 65 pieces
1 min → 65 ÷ 5 = 13 pieces
Time taken by Machine C alone:
11 min → 132 pieces
1 min → 132 ÷ 11 = 12 pieces
Time taken by Machine D alone:
9 min → 132 pieces
1 min → 99 ÷ 9 = 11 pieces
Time taken by Machine B and Machine C together:
1 min → 13 + 12 = 25 pieces
Time taken by Machine C and Machine D together:
1 min → 12 + 11 = 23 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
= 25 - 23
= 2
Answer(s): (a) B, C or C, B; (b) 2