When Pedro called Gary, the call cost $1.58. If the rate for the call was .53 cents for the first three minutes and .15 for each additional minute or fraction thereof, how long did Pedro and Gary talk?

cost $1.58

.53 cents / 3 minutes

.15 cents x

.53 + .15x = $1.58

is this the correct equation, if so how is 10 the answer