There are 2 groups of operators in a factory. There are 5 more operators in the first group than the second group. Each operator in the first group makes 6 toys in a minute but each operator in the second group makes only 4 toys in a minute. Both groups make a total of 18000 toys in 2 hours.

1. How many operators are there in the first group?
2. How many operators are there in the second group?

	First group	Second group
Number	1 u + 5	1 u
Value	6	4
Total value	6 u + 30	4 u

Number of operators in first group = 1 u + 5
Number of operators in second group = 1 u

Total number of toys made 
= 6 u + 30 + 4 u 
= 10 u + 30 

1 h = 60 min
2 h = 2 x 60 = 120 min

Total number of toys made in 1 min
= 18000 ÷ 120
= 150

10 u + 30 = 150
10 u = 150 - 30
10 u = 120

1 u = 120 ÷ 10 = 12

Number of operators in the first group
= 1 u + 5
= 12 + 5
= 17

(b)
Number of operators in the second group
= 1 u
= 12

Answer(s): (a) 17; (b) 12