Walter works 5 days a week in a fast-food chain and earns $5 per hour. Since he is a working student, he can only work 4 hours a day and allocates 3/4 of his weekly earning for his schooling. How much does he allocate for school? Let's think first. Chain of thought:
Walter's daily earning is $5 x 4 = $20. So he earns $20 x 5 = $100 per week. Therefore, he allocates $100 x 3 / 4 = $75 for his school.
Therefore, the answer is 75.