## Basic College Mathematics (9th Edition)

We see that the cost per minute to the Philippines is: $\$0.084/minute$. Since you made a 95 minute phone call, the total cost was:$0.084*95=\$7.98$ Since you started with $\$20$, the amount left is:$20-7.98=\$12.02$ Thus you can use this amount to call Afghanistan at a rate of $\$0.134$:$12.02\div 0.134\approx 89.7\approx89\$ minutes (We round down because you do not have enough funds for the last minute.) Therefore, your call to Afghanistan can last 89 minutes.