Machine H takes 10 minutes to cut 100 pieces of lumbers. Machine J takes 20 minutes to cut 220 pieces of lumbers. Machine K takes 12 minutes to cut 144 pieces of lumber.
- Which is the faster combination, H and J or J and K? (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 H alone:
10 min → 100 pieces
1 min → 100 ÷ 10 = 10 pieces
Time taken by Machine J alone:
20 min → 220 pieces
1 min → 220 ÷ 20 = 11 pieces
Time taken by Machine K alone:
12 min → 220 pieces
1 min → 144 ÷ 12 = 12 pieces
Time taken by Machine H and Machine J together:
1 min → 10 + 11 = 21 pieces
Time taken by Machine J and Machine K together:
1 min → 11 + 12 = 23 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
= 23 - 21
= 2
Answer(s): (a) J, K or K, J; (b) 2