Answer:
30
Explanation:
Provided that there are two categories of workers:
Blue Collar and white collar
Rate of blue collar = $600 per week
Rate of white collar = $1,000 per week
Total workers = 50
Let us assume that blue collar workers = y
Then,
y $600 + (50 - y) $1,000 = $42,000
600y + $50,000 - 1,000y = $42,000
$50,000 - $42,000 = 1,000y - 600y
$8,000 = 400y
$8,000/400 = y
20 = y
That means 20 blue collar workers
White collar workers = 50 - y = 50 - 20 = 30