Question

1My little sister, Savannah, is three years old and has a piggy bank that she wants to fill. She

started with five pennies and each day when I come home from school, she is excited when I give her three pennies that are left over from my lunch money. How much money will Savannah have after 10 days? How many days will it take for her to have at least $1.50? Justify your answer with a mathematical model of the problem situation.

Answer 1

Savannah will have 35 pennies after 10 days.

It will take her 49 days to have at least $1.50

Explanation:

Start Value = .05

Linear Increase = .03

.05 + .03x = TV

TV = Total Value

10 days = .05 + .03(10)

10 days = $.35

.05 + .03x = 1.50

1.50 - .05 = 1.45

1.45/.03 = 48.33

48 days is not enough for her to have 1.50 as she is not gaining hourly but rather daily so it would take her 49 days to have at least 49