Machine H takes 7 minutes to cut 70 pieces of lumbers. Machine J takes 12 minutes to cut 132 pieces of lumbers. Machine K takes 13 minutes to cut 169 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:
7 min → 70 pieces
1 min → 70 ÷ 7 = 10 pieces
Time taken by Machine J alone:
12 min → 132 pieces
1 min → 132 ÷ 12 = 11 pieces
Time taken by Machine K alone:
13 min → 132 pieces
1 min → 169 ÷ 13 = 13 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 + 13 = 24 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
= 24 - 21
= 3
Answer(s): (a) J, K or K, J; (b) 3