Answer:
$138
Step-by-step explanation:
Let the money with Raymond be $y
Let the cost of 1 tshirt be $x
then cost of 8 tshirt = cost of 1 t-shirt*8 = 8x
Raymond wanted to buy 8 t-shirt but he was short of $8.10
It means that 8x is equal to money he had plus $8.10
thus,
y + 8.10 = 8x
y = 8x - 8.10
Next situation
cost of 5 t-shirt = 5x
. instead he bought 5 T-shirt and had $12.60 left,
it means cost of 5 T-shirt plus $12.60 = total money Raymond had
y = 5x + 12.60
comparing y in both the equation
y = 8x - 8.10 and y = 8x - 8.10
5x + 12.60 = 8x - 8.10
=> 8x-5x = 12.60+8.10
=> 3x = 20.70
=> x = 20.70/3 = 6.9
Thus, cost of 1 T-shirt = $6.9
cost of 20 T-shirt = 20*$6.9 = $138 (Answer)
