Question

mary bought a gift card and loaded it with some money. each month, she withdraws her cell phone bill automatically from the card. the table below shows the remaining balance on marys gift card after 5 months.

how much money did mary initially load onto her gift card, and how much is her monthly cell phone plan?
a initially loaded: $600; monthly plan: $60
b initially loaded: $680; monthly plan: $60
c initially loaded: $620; monthly plan: $60
d initially loaded: $620; monthly plan: $70

Explanation:

Step1: Calculate the monthly withdrawal

The balance changes from $500 (month 2) to $440 (month 3). The difference is \(500 - 440=\$60\). Check other consecutive months: \(440 - 380 = 60\), \(380-320 = 60\). So the monthly plan is \(\$60\).

Step2: Find the initial amount

Let the initial amount be \(y\). After 2 months, the balance is \(y-2\times60\). Since at month 2 the balance is \(500\), we have the equation \(y - 2\times60=500\). Solve for \(y\): \(y=500 + 120=\$620\).

Answer:

C. Initially loaded: $620; monthly plan: $60