There are 2 groups of workers in a factory. There are 3 more workers in the first group than the second group. Each worker in the first group makes 7 toys in a minute but each worker in the second group makes only 4 toys in a minute. Both groups make a total of 52500 toys in 5 hours.

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

	First group	Second group
Number	1 u + 3	1 u
Value	7	4
Total value	7 u + 21	4 u

Number of workers in first group = 1 u + 3
Number of workers in second group = 1 u

Total number of toys made 
= 7 u + 21 + 4 u 
= 11 u + 21 

1 h = 60 min
5 h = 5 x 60 = 300 min

Total number of toys made in 1 min
= 52500 ÷ 300
= 175

11 u + 21 = 175
11 u = 175 - 21
11 u = 154

1 u = 154 ÷ 11 = 14

Number of workers in the first group
= 1 u + 3
= 14 + 3
= 17

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

Answer(s): (a) 17; (b) 14