Respuesta :
Assume that Chris began with m dollars in his pocket.
Half of that, or m/2, went to purchase a pair of headphones.
Half of that, or (1/2)(m/2), or m/4, went to purchasing CDs. By now Chris has spent (1/2 + 1/4) of his money: (3/4)m. He had (1/4)m left, and that (m/4) = $12.75.
Solve this for m:
$12.75
m = ------------ = $5 (answer).
(1/4)
Half of that, or m/2, went to purchase a pair of headphones.
Half of that, or (1/2)(m/2), or m/4, went to purchasing CDs. By now Chris has spent (1/2 + 1/4) of his money: (3/4)m. He had (1/4)m left, and that (m/4) = $12.75.
Solve this for m:
$12.75
m = ------------ = $5 (answer).
(1/4)