Machine V takes 10 minutes to cut 200 pieces of lumbers. Machine W takes 12 minutes to cut 144 pieces of lumbers. Machine X takes 11 minutes to cut 165 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:
10 min → 200 pieces
1 min → 200 ÷ 10 = 20 pieces

Time taken by Machine W alone:
12 min → 144 pieces
1 min → 144 ÷ 12 = 12 pieces

Time taken by Machine X alone:
11 min → 144 pieces
1 min → 165 ÷ 11 = 15 pieces

Time taken by Machine V and Machine W together:
1 min → 20 + 12 = 32 pieces

Time taken by Machine W and Machine X together:
1 min → 12 + 15 = 27 pieces

Machine V and W are the faster combination.

(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine V and W) in 1 minute
= 32 - 27
= 5 

Answer(s): (a) V, W or W, V; (b) 5