Machine J takes 7 minutes to cut 77 pieces of lumbers. Machine K takes 13 minutes to cut 156 pieces of lumbers. Machine L takes 12 minutes to cut 168 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 → 77 pieces
1 min → 77 ÷ 7 = 11 pieces
Time taken by Machine K alone:
13 min → 156 pieces
1 min → 156 ÷ 13 = 12 pieces
Time taken by Machine L alone:
12 min → 156 pieces
1 min → 168 ÷ 12 = 14 pieces
Time taken by Machine J and Machine K together:
1 min → 11 + 12 = 23 pieces
Time taken by Machine K and Machine L together:
1 min → 12 + 14 = 26 pieces
Machine K and L are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine K and L) in 1 minute
= 26 - 23
= 3
Answer(s): (a) K, L or L, K; (b) 3