Machine Q takes 10 minutes to cut 200 pieces of lumbers. Machine R takes 18 minutes to cut 108 pieces of lumbers. Machine S takes 12 minutes to cut 216 pieces of lumber.
- Which is the faster combination, Q and R or R and S? (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 Q alone:
10 min → 200 pieces
1 min → 200 ÷ 10 = 20 pieces
Time taken by Machine R alone:
18 min → 108 pieces
1 min → 108 ÷ 18 = 6 pieces
Time taken by Machine S alone:
12 min → 108 pieces
1 min → 216 ÷ 12 = 18 pieces
Time taken by Machine Q and Machine R together:
1 min → 20 + 6 = 26 pieces
Time taken by Machine R and Machine S together:
1 min → 6 + 18 = 24 pieces
Machine Q and R are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine Q and R) in 1 minute
= 26 - 24
= 2
Answer(s): (a) Q, R or R, Q; (b) 2