Machine F takes 5 minutes to cut 90 pieces of lumbers. Machine G takes 16 minutes to cut 176 pieces of lumbers. Machine H takes 11 minutes to cut 165 pieces of lumber. 

1. Which is the faster combination, F and G or G and H? (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 F alone:
5 min → 90 pieces
1 min → 90 ÷ 5 = 18 pieces

Time taken by Machine G alone:
16 min → 176 pieces
1 min → 176 ÷ 16 = 11 pieces

Time taken by Machine H alone:
11 min → 176 pieces
1 min → 165 ÷ 11 = 15 pieces

Time taken by Machine F and Machine G together:
1 min → 18 + 11 = 29 pieces

Time taken by Machine G and Machine H together:
1 min → 11 + 15 = 26 pieces

Machine F and G are the faster combination.

(b)
Number of more pieces of lumbers that can be cut by the faster combination (Machine F and G) in 1 minute
= 29 - 26
= 3 

Answer(s): (a) F, G or G, F; (b) 3