Machine D takes 11 minutes to cut 220 pieces of lumbers. Machine E takes 12 minutes to cut 72 pieces of lumbers. Machine F takes 7 minutes to cut 84 pieces of lumber.
- Which is the faster combination, D and E or E and F? (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 D alone:
11 min → 220 pieces
1 min → 220 ÷ 11 = 20 pieces
Time taken by Machine E alone:
12 min → 72 pieces
1 min → 72 ÷ 12 = 6 pieces
Time taken by Machine F alone:
7 min → 72 pieces
1 min → 84 ÷ 7 = 12 pieces
Time taken by Machine D and Machine E together:
1 min → 20 + 6 = 26 pieces
Time taken by Machine E and Machine F together:
1 min → 6 + 12 = 18 pieces
Machine D and E are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine D and E) in 1 minute
= 26 - 18
= 8
Answer(s): (a) D, E or E, D; (b) 8