Machine Q takes 8 minutes to cut 88 pieces of lumbers. Machine R takes 18 minutes to cut 162 pieces of lumbers. Machine S takes 9 minutes to cut 135 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:
8 min → 88 pieces
1 min → 88 ÷ 8 = 11 pieces
Time taken by Machine R alone:
18 min → 162 pieces
1 min → 162 ÷ 18 = 9 pieces
Time taken by Machine S alone:
9 min → 162 pieces
1 min → 135 ÷ 9 = 15 pieces
Time taken by Machine Q and Machine R together:
1 min → 11 + 9 = 20 pieces
Time taken by Machine R and Machine S together:
1 min → 9 + 15 = 24 pieces
Machine R and S are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine R and S) in 1 minute
= 24 - 20
= 4
Answer(s): (a) R, S or S, R; (b) 4