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 were 4−inch bolts that cost 42 cents each. How many 3−inch bolts did James buy?

Answer 1

x = 3 -inch bolts

y = 4 -inch bolts

James bought 24 bolts.

This mean x + y = 24

36 cents = $ 0.36

42 cents = $ 0.42

Total price = $ 9

This mean :

0.36 x + 0.42 y = 9

Now you must solve system :

x + y = 24

0.36 x + 0.42 y = 9

Try.

Answer 2

15

Answer 3

0.36(18) + 0.42(6)
=6.48+2.52
=9.00

X (3-inch bolts)= 18
Y (4-inch bolts) = 6