Question

Lisa's penny bank is 1/10 full. After she adds 440 pennies, it is 3/5 full. How many pennies can Lisa's bank hold?

Answer 1

Answer:

Step-by-step explanation:

After the 440 pennies are added, the bank is 3/5 full.  It started out 1/10 full, so

3/5 - 1/10 is the amount of space in the bank that the 440 pennies took up, or

1/2.  Use proportions to solve this, with number of pennies on the top and the fraction of the bank that is filled on the bottom:

$\frac{440}{\frac{1}{2} }=\frac{x}{1}$

where x is the number of pennies (our unknown) that it will take to fill the bank (1).  Cross multiply to get

$\frac{1}{2}x=440$

so x = 880