Machine X takes 5 minutes to cut 55 pieces of lumbers. Machine Y takes 20 minutes to cut 200 pieces of lumbers. Machine Z takes 9 minutes to cut 117 pieces of lumber.
- Which is the faster combination, X and Y or Y and Z? (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 X alone:
5 min → 55 pieces
1 min → 55 ÷ 5 = 11 pieces
Time taken by Machine Y alone:
20 min → 200 pieces
1 min → 200 ÷ 20 = 10 pieces
Time taken by Machine Z alone:
9 min → 200 pieces
1 min → 117 ÷ 9 = 13 pieces
Time taken by Machine X and Machine Y together:
1 min → 11 + 10 = 21 pieces
Time taken by Machine Y and Machine Z together:
1 min → 10 + 13 = 23 pieces
Machine Y and Z are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine Y and Z) in 1 minute
= 23 - 21
= 2
Answer(s): (a) Y, Z or Z, Y; (b) 2