Machine C takes 10 minutes to cut 120 pieces of lumbers. Machine D takes 14 minutes to cut 154 pieces of lumbers. Machine E takes 15 minutes to cut 210 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:
10 min → 120 pieces
1 min → 120 ÷ 10 = 12 pieces
Time taken by Machine D alone:
14 min → 154 pieces
1 min → 154 ÷ 14 = 11 pieces
Time taken by Machine E alone:
15 min → 154 pieces
1 min → 210 ÷ 15 = 14 pieces
Time taken by Machine C and Machine D together:
1 min → 12 + 11 = 23 pieces
Time taken by Machine D and Machine E together:
1 min → 11 + 14 = 25 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
= 25 - 23
= 2
Answer(s): (a) D, E or E, D; (b) 2