i feel like i should know this but i guess not

Question

There are 12 boxes stacked on a shelf. The height of each box is either 2 inches or 3 inches. The height of the stack of 12 boxes is 30 inches. Which system of equations can be used to find 

x, the number of 2-inch-thick boxes, and y, the number of 3-inch-thick boxes?

 

 

3x+2y = 30x+y = 12

⊝

2x+3y = 12x+y = 30

⊝

2x+3y = 30x+y = 12

⊝

3x+2y = 12x+y = 30

⊝

CLEAR ALL

Answer 1

Hi,

The right answer is 2x+3y = 30 x+y = 12

Because the number of boxes are 12 that it means add of y and x.

And 30 inches is possibility of making boxes next to each other.

After solving this system you will have x = 6 & y = 6.

I hope it is useful,

Minoo