Machine C takes 7 minutes to cut 119 pieces of lumbers. Machine D takes 20 minutes to cut 160 pieces of lumbers. Machine E takes 11 minutes to cut 154 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:
7 min → 119 pieces
1 min → 119 ÷ 7 = 17 pieces
Time taken by Machine D alone:
20 min → 160 pieces
1 min → 160 ÷ 20 = 8 pieces
Time taken by Machine E alone:
11 min → 160 pieces
1 min → 154 ÷ 11 = 14 pieces
Time taken by Machine C and Machine D together:
1 min → 17 + 8 = 25 pieces
Time taken by Machine D and Machine E together:
1 min → 8 + 14 = 22 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