Question
Machine C takes 9 minutes to cut 90 pieces of lumbers. Machine D takes 14 minutes to cut 84 pieces of lumbers. Machine E takes 8 minutes to cut 112 pieces of lumber. 
  1. Which is the faster combination, C and D or D and E? (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?
3 m
(a)

Click button first when a symbol is required. X

(b)

Click button first when a symbol is required. X

Machine C takes 9 minutes to cut 90 pieces of lumbers. Machine D takes 14 minutes to cut 84 pieces of lumbers. Machine E takes 8 minutes to cut 112 pieces of lumber. 
  1. Which is the faster combination, C and D or D and E? (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?