Answer:
Lina spent 28 minutes on the call.
Step-by-step explanation:
let n be the number of minutes lina made a call
then:
cost of long distance call is 16 cents/min = 0.16 dollars/min
number of dollars spent on the long distance call = 0.16n
if the total dollars of the phone card is $15 and the remaining dollars after the call is $10.52, this implies that:
$15 = $10.52 + (0.16n)$
n = (15 - 10.52)/0.16
= 28
Therefore, lina spent 28 minutes on the call.