Algebra Question

Question

James bought 32 bolts at the hardware store for a total of $12.00. 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+Y = 32 <--- 32 bolts purchased

36X + 42Y = 1200 <--- amounts in pennies, for a total of $12

Y = 32-x per first equation

36X + 42( 32 - x) = 1200

36X + 1344 - 42x = 1200

1344 - 6x = 1200

-6x = -144

x = 24

24 of the 3" bolts

8 of the 4" bolts

yes it checks: 36*24 + 42*8 = 1200 pennies

Answer 2

No. of 3 inches ball = x

no. of 4 inches ball =y

total price for 3 inches ball = 0.36x

total price for 4 inches ball =0.42y

x+y =32

0.36x+0.42y=12

solve these 2 equation and find the value of x and y