Question

Alexander finds some nickels and pennies in his piggy bank. How much money (in dollars) does he have if he has 70 nickels and 100 pennies? How much money (in dollars) does he have if he has x nickels and y pennies?The total value, 70 nickels and 100 pennies (dollars): The total value, x nickels and y pennies (dollars):

Answer 1

A nickel is equivalent to 0.05 dollars while a penny is equivalent to 0.01 dollars.

a) Therefore if D is the total number of dollars,

`\begin{gathered} D=0.05\cdot70+0.01\cdot100=3.5+1=4.5 \\ \Rightarrow D=4.5 \end{gathered}`

Therefore, the answer to the first question is 4.5 dollars.

b) Similarly, if one has x nickels and y pennies,

`D=0.05x+0.01y`

The answer to the second question is 0.05x+0.01y