Machine U takes 10 minutes to cut 180 pieces of lumbers. Machine V takes 20 minutes to cut 140 pieces of lumbers. Machine W takes 7 minutes to cut 77 pieces of lumber.
- Which is the faster combination, U and V or V and W? (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 U alone:
10 min → 180 pieces
1 min → 180 ÷ 10 = 18 pieces
Time taken by Machine V alone:
20 min → 140 pieces
1 min → 140 ÷ 20 = 7 pieces
Time taken by Machine W alone:
7 min → 140 pieces
1 min → 77 ÷ 7 = 11 pieces
Time taken by Machine U and Machine V together:
1 min → 18 + 7 = 25 pieces
Time taken by Machine V and Machine W together:
1 min → 7 + 11 = 18 pieces
Machine U and V are the faster combination.
(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine U and V) in 1 minute
= 25 - 18
= 7
Answer(s): (a) U, V or V, U; (b) 7