Machine C takes 10 minutes to cut 100 pieces of lumbers. Machine D takes 13 minutes to cut 78 pieces of lumbers. Machine E takes 8 minutes to cut 104 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 → 100 pieces
1 min → 100 ÷ 10 = 10 pieces
Time taken by Machine D alone:
13 min → 78 pieces
1 min → 78 ÷ 13 = 6 pieces
Time taken by Machine E alone:
8 min → 78 pieces
1 min → 104 ÷ 8 = 13 pieces
Time taken by Machine C and Machine D together:
1 min → 10 + 6 = 16 pieces
Time taken by Machine D and Machine E together:
1 min → 6 + 13 = 19 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
= 19 - 16
= 3
Answer(s): (a) D, E or E, D; (b) 3