Answer:
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.
