james bought 24 bolts at the hardware store for a total of $9.00. some were 3-inch bolts that cost 36 cents each and the others are 4-inch bolts that cost 42 cents each. How many 3-inch bolts did james buy?

Answer 1

Let's assume that James bought x 3-inch bolts.
Then, he bought 24 - x 4-inch bolts.
The cost of x 3-inch bolts is 36x cents.
The cost of (24 - x) 4-inch bolts is 42(24 - x) cents.
The total cost of the bolts is 36x + 42(24 - x) cents.
Since the total cost is $9.00, we can write the equation:
36x + 42(24 - x) = 900.
Expanding the expression, we get:
36x + 1008 - 42x = 900.
Combining like terms, we get:
-6x + 1008 = 900.
Subtracting 1008 from both sides, we get:
-6x = -108.
Dividing both sides by -6, we get:
x = 18.
Therefore, James bought 18 3-inch bolts. Answer: \boxed{18}.