Machine C takes 8 minutes to cut 80 pieces of lumbers. Machine D takes 19 minutes to cut 209 pieces of lumbers. Machine E takes 15 minutes to cut 225 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 → 80 pieces
1 min → 80 ÷ 8 = 10 pieces
Time taken by Machine D alone:
19 min → 209 pieces
1 min → 209 ÷ 19 = 11 pieces
Time taken by Machine E alone:
15 min → 209 pieces
1 min → 225 ÷ 15 = 15 pieces
Time taken by Machine C and Machine D together:
1 min → 10 + 11 = 21 pieces
Time taken by Machine D and Machine E together:
1 min → 11 + 15 = 26 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 - 21
= 5
Answer(s): (a) D, E or E, D; (b) 5