Machine Z takes 9 minutes to cut 162 pieces of lumbers. Machine A takes 11 minutes to cut 77 pieces of lumbers. Machine B takes 12 minutes to cut 168 pieces of lumber.
- Which is the faster combination, Z and A or A and B? (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 Z alone:
9 min → 162 pieces
1 min → 162 ÷ 9 = 18 pieces
Time taken by Machine A alone:
11 min → 77 pieces
1 min → 77 ÷ 11 = 7 pieces
Time taken by Machine B alone:
12 min → 77 pieces
1 min → 168 ÷ 12 = 14 pieces
Time taken by Machine Z and Machine A together:
1 min → 18 + 7 = 25 pieces
Time taken by Machine A and Machine B together:
1 min → 7 + 14 = 21 pieces
Machine Z and A are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine Z and A) in 1 minute
= 25 - 21
= 4
Answer(s): (a) Z, A or A, Z; (b) 4
