Machine C takes 8 minutes to cut 144 pieces of lumbers. Machine D takes 15 minutes to cut 180 pieces of lumbers. Machine E takes 7 minutes to cut 112 pieces of lumber.
- Which is the faster combination, C and D or D and E? (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 C alone:
8 min → 144 pieces
1 min → 144 ÷ 8 = 18 pieces
Time taken by Machine D alone:
15 min → 180 pieces
1 min → 180 ÷ 15 = 12 pieces
Time taken by Machine E alone:
7 min → 180 pieces
1 min → 112 ÷ 7 = 16 pieces
Time taken by Machine C and Machine D together:
1 min → 18 + 12 = 30 pieces
Time taken by Machine D and Machine E together:
1 min → 12 + 16 = 28 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
= 30 - 28
= 2
Answer(s): (a) C, D or D, C; (b) 2