Question

Jon buys staplers and three hole punches. He spends $112 on them in total. Each stapler is $7 and each three hole punch is $12. If he buys 11 items in all how many staplers and three hole punches did he purchase ?

Answer 1

Answer: Jon purchased 4 staplers and 7 three hole punchers.

Step-by-step explanation:

Let x be the number of staplers and y be the number of three hole punches purchased by Jon.

Then the equation for total items will be

$x+y=11$............(1)

And the equation for the total cost will be

$7x+12y=112$........................(2)

Multiply eq(1) by 7 and then subtract from eq (2), we get

$7x+12y-(7x+7y)=112-7(11)\\\Rightarrow5y=112-77\\\Rightarrow\ 5=35\\\Rightarrow\ y=7$

Put y=7 in eq(1), we get x= 4.

Hence, Jon purchased 4 staplers and 7 three hole punchers.