Machine F takes 7 minutes to cut 70 pieces of lumbers. Machine G takes 10 minutes to cut 70 pieces of lumbers. Machine H takes 9 minutes to cut 126 pieces of lumber.
- Which is the faster combination, F and G or G and H? (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 F alone:
7 min → 70 pieces
1 min → 70 ÷ 7 = 10 pieces
Time taken by Machine G alone:
10 min → 70 pieces
1 min → 70 ÷ 10 = 7 pieces
Time taken by Machine H alone:
9 min → 70 pieces
1 min → 126 ÷ 9 = 14 pieces
Time taken by Machine F and Machine G together:
1 min → 10 + 7 = 17 pieces
Time taken by Machine G and Machine H together:
1 min → 7 + 14 = 21 pieces
Machine G and H are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine G and H) in 1 minute
= 21 - 17
= 4
Answer(s): (a) G, H or H, G; (b) 4
