For every magazine Tommy sells, he gets $1.75 as commission. He gets an additional $1.50 for every 8 magazine sold. How many magazines did Tommy sell if he earned $50 in commission?

Answer 1

assuming he only makes the $1.50 every time a multiple of 8 magazines is sold, that is he gets it on the sale of the 8th, 16th, etc. ... zines, then if he sells x magazines,
1.75x + 1.50⌊(x-1)/8⌋ = 50
x = 26
Check:
$1.75 * 26 = $45.50
$1.50 * 3 = $4.50
does that make $50? yes.