Question

1.Lucy and her sister, Maya, need money for lunch. Their mother gives each of them the sameamount of money, Lucy receives three dollar bills and 5 coins. Maya receive 7 dollar bills and 4coins. If the coins each girl receive have the same value, find c, the value of one coin.

Answer 1

Let's define some notation first.

M = amount of money for Maya. L= amount of money for Lucy

We also know that Lucy receives three dollar bills and 5 coins and Maya receive 7 dollar bills and 4coins. by the way we also know that the coins each girl receive have the same value

Since both have the same amount of money we have this:

`M\text{ = L (1)}`

From the second condition we have this:

`M\text{ = 7 + 4c (2)}`
`L=3+5c\text{ (3)}`

Now we can replace equations (2) and (3) into equation (1) and we got:

`7+4c=\text{ 3+5c}`

And now we can solve for the value of c

`7+4c-4c=\text{ 3+5c}-4c`
`7=\text{ 3+c}`
`7-3=c=4`

Then we can see that the value for each of the cins is 4