There are 2 groups of operators in a factory. There are 7 more operators in the first group than the second group. Each operator in the first group makes 4 toys in a minute but each operator in the second group makes only 2 toys in a minute. Both groups make a total of 26880 toys in 4 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 + 7	1 u
Value	4	2
Total value	4 u + 28	2 u

Number of operators in first group = 1 u + 7
Number of operators in second group = 1 u

Total number of toys made 
= 4 u + 28 + 2 u 
= 6 u + 28 

1 h = 60 min
4 h = 4 x 60 = 240 min

Total number of toys made in 1 min
= 26880 ÷ 240
= 112

6 u + 28 = 112
6 u = 112 - 28
6 u = 84

1 u = 84 ÷ 6 = 14

Number of operators in the first group
= 1 u + 7
= 14 + 7
= 21

(b)
Number of operators in the second group
= 1 u
= 14

Answer(s): (a) 21; (b) 14