Question

On his last credit card bill, Frank paid a variable finance rate of 1.5 percent on the first $500, and 1 percent

on any amount above $500. How much did he pay if the unpaid balance was $741.23?
$11.12
$9.91
$7.41
$6.52

Answer 1

• $ 9.91

Step-by-step explanation:

The amount that Frank paid on his last credit card bill shows how piecewise functions work.

Taking into account that:

• 1.5 percent = 1.5/100 = 0.015,
• 1 percent = 1 / 100 = 0.01, and
• 0.015 × 500 = 7.50,

You can model the amount paid using the piecewise function p(x):

• 
  `p(x)=\left \{ {{0.015x;x\leq500 } \atop {\\}{7.50+0.01(x-500);x>500}} \right.`

Thus, your calculation is:

• x = $741.23

• p(x) = $7.50 + $ 0.01 × (741.23 - 500) = $ 9.91