Machine S takes 11 minutes to cut 154 pieces of lumbers. Machine T takes 15 minutes to cut 90 pieces of lumbers. Machine U takes 10 minutes to cut 120 pieces of lumber.
- Which is the faster combination, S and T or T and U? (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 S alone:
11 min → 154 pieces
1 min → 154 ÷ 11 = 14 pieces
Time taken by Machine T alone:
15 min → 90 pieces
1 min → 90 ÷ 15 = 6 pieces
Time taken by Machine U alone:
10 min → 90 pieces
1 min → 120 ÷ 10 = 12 pieces
Time taken by Machine S and Machine T together:
1 min → 14 + 6 = 20 pieces
Time taken by Machine T and Machine U together:
1 min → 6 + 12 = 18 pieces
Machine S and T are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine S and T) in 1 minute
= 20 - 18
= 2
Answer(s): (a) S, T or T, S; (b) 2