Machine G takes 10 minutes to cut 180 pieces of lumbers. Machine H takes 20 minutes to cut 120 pieces of lumbers. Machine J takes 7 minutes to cut 91 pieces of lumber.
- Which is the faster combination, G and H or H and J? (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 G alone:
10 min → 180 pieces
1 min → 180 ÷ 10 = 18 pieces
Time taken by Machine H alone:
20 min → 120 pieces
1 min → 120 ÷ 20 = 6 pieces
Time taken by Machine J alone:
7 min → 120 pieces
1 min → 91 ÷ 7 = 13 pieces
Time taken by Machine G and Machine H together:
1 min → 18 + 6 = 24 pieces
Time taken by Machine H and Machine J together:
1 min → 6 + 13 = 19 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
= 24 - 19
= 5
Answer(s): (a) G, H or H, G; (b) 5