Machine J takes 7 minutes to cut 112 pieces of lumbers. Machine K takes 20 minutes to cut 180 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:
7 min → 112 pieces
1 min → 112 ÷ 7 = 16 pieces
Time taken by Machine K alone:
20 min → 180 pieces
1 min → 180 ÷ 20 = 9 pieces
Time taken by Machine L alone:
9 min → 180 pieces
1 min → 108 ÷ 9 = 12 pieces
Time taken by Machine J and Machine K together:
1 min → 16 + 9 = 25 pieces
Time taken by Machine K and Machine L together:
1 min → 9 + 12 = 21 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
= 25 - 21
= 4
Answer(s): (a) J, K or K, J; (b) 4