Machine A takes 7 minutes to cut 77 pieces of lumbers. Machine B takes 13 minutes to cut 91 pieces of lumbers. Machine C takes 15 minutes to cut 195 pieces of lumber.
- Which is the faster combination, A and B or B and C? (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 A alone:
7 min → 77 pieces
1 min → 77 ÷ 7 = 11 pieces
Time taken by Machine B alone:
13 min → 91 pieces
1 min → 91 ÷ 13 = 7 pieces
Time taken by Machine C alone:
15 min → 91 pieces
1 min → 195 ÷ 15 = 13 pieces
Time taken by Machine A and Machine B together:
1 min → 11 + 7 = 18 pieces
Time taken by Machine B and Machine C together:
1 min → 7 + 13 = 20 pieces
Machine B and C are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine B and C) in 1 minute
= 20 - 18
= 2
Answer(s): (a) B, C or C, B; (b) 2