Marge purchased bicycle helmets and tire pumps. Each helmet cost $12.00 and each pump cost $8.00. She purchased a total of 18 items and spent $188.00. How many helmets did Marge buy?

11

Step-by-step explanation:

Let the no. of helmet be x

cost of 1 helmet = $12.00

cost of x helmet = $12.00*x = $12x

Let the no. of tire pumps be y

cost of 1 tire pumps = $8.00

cost of x tire pumps = $8.00*y = $8y

Given that total no. of helmet and pump is 18

thus

x + y = 18

y = 18-x

also given

total money spent is $188

thus

12x+8y = 188

using y = 18 - x

we have

12x + 8(18-x) = 188

=> 12x+ 144 - 8x = 188

=> 4x = 188-144 = 44

=> x = 44/4 = 11

Thus, no of helmet bought by Margo is 11.

trapezoid

step-by-step explanation:

first i plotted all my points on a grid graph

i made sure all of them were in the correct quadrant

then i saw it was a trapezoid or a quadrilateral

answer: 1 + 1 = 11

step-by-step explanation: