Machine V takes 6 minutes to cut 66 pieces of lumbers. Machine W takes 10 minutes to cut 120 pieces of lumbers. Machine X takes 9 minutes to cut 117 pieces of lumber. 

1. Which is the faster combination, V and W or W and X? (Eg A, B) 
2. 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 V alone:
6 min → 66 pieces
1 min → 66 ÷ 6 = 11 pieces

Time taken by Machine W alone:
10 min → 120 pieces
1 min → 120 ÷ 10 = 12 pieces

Time taken by Machine X alone:
9 min → 120 pieces
1 min → 117 ÷ 9 = 13 pieces

Time taken by Machine V and Machine W together:
1 min → 11 + 12 = 23 pieces

Time taken by Machine W and Machine X together:
1 min → 12 + 13 = 25 pieces

Machine W and X are the faster combination.

(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine W and X) in 1 minute
= 25 - 23
= 2 

Answer(s): (a) W, X or X, W; (b) 2