Machine P takes 7 minutes to cut 77 pieces of lumbers. Machine Q takes 16 minutes to cut 128 pieces of lumbers. Machine R takes 13 minutes to cut 182 pieces of lumber.
- Which is the faster combination, P and Q or Q and R? (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 P alone:
7 min → 77 pieces
1 min → 77 ÷ 7 = 11 pieces
Time taken by Machine Q alone:
16 min → 128 pieces
1 min → 128 ÷ 16 = 8 pieces
Time taken by Machine R alone:
13 min → 128 pieces
1 min → 182 ÷ 13 = 14 pieces
Time taken by Machine P and Machine Q together:
1 min → 11 + 8 = 19 pieces
Time taken by Machine Q and Machine R together:
1 min → 8 + 14 = 22 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
= 22 - 19
= 3
Answer(s): (a) Q, R or R, Q; (b) 3