Machine Q takes 12 minutes to cut 216 pieces of lumbers. Machine R takes 17 minutes to cut 170 pieces of lumbers. Machine S takes 8 minutes to cut 104 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:
12 min → 216 pieces
1 min → 216 ÷ 12 = 18 pieces
Time taken by Machine R alone:
17 min → 170 pieces
1 min → 170 ÷ 17 = 10 pieces
Time taken by Machine S alone:
8 min → 170 pieces
1 min → 104 ÷ 8 = 13 pieces
Time taken by Machine Q and Machine R together:
1 min → 18 + 10 = 28 pieces
Time taken by Machine R and Machine S together:
1 min → 10 + 13 = 23 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
= 28 - 23
= 5
Answer(s): (a) Q, R or R, Q; (b) 5