Machine B takes 7 minutes to cut 84 pieces of lumbers. Machine C takes 13 minutes to cut 130 pieces of lumbers. Machine D takes 10 minutes to cut 150 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:
7 min → 84 pieces
1 min → 84 ÷ 7 = 12 pieces
Time taken by Machine C alone:
13 min → 130 pieces
1 min → 130 ÷ 13 = 10 pieces
Time taken by Machine D alone:
10 min → 130 pieces
1 min → 150 ÷ 10 = 15 pieces
Time taken by Machine B and Machine C together:
1 min → 12 + 10 = 22 pieces
Time taken by Machine C and Machine D together:
1 min → 10 + 15 = 25 pieces
Machine C and D are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine C and D) in 1 minute
= 25 - 22
= 3
Answer(s): (a) C, D or D, C; (b) 3