Machine J takes 5 minutes to cut 90 pieces of lumbers. Machine K takes 15 minutes to cut 150 pieces of lumbers. Machine L takes 9 minutes to cut 108 pieces of lumber.
- Which is the faster combination, J and K or K and L? (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 J alone:
5 min → 90 pieces
1 min → 90 ÷ 5 = 18 pieces
Time taken by Machine K alone:
15 min → 150 pieces
1 min → 150 ÷ 15 = 10 pieces
Time taken by Machine L alone:
9 min → 150 pieces
1 min → 108 ÷ 9 = 12 pieces
Time taken by Machine J and Machine K together:
1 min → 18 + 10 = 28 pieces
Time taken by Machine K and Machine L together:
1 min → 10 + 12 = 22 pieces
Machine J and K are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine J and K) in 1 minute
= 28 - 22
= 6
Answer(s): (a) J, K or K, J; (b) 6