Rina saves $4.50 each week. Her sister save $2 more each week. When her sister has saved $14 more than Rina, how much has Rina saved?
at $2/week, it takes 7 weeks for the sister to save $14 more.
So, in those 7 weeks, Rina has saved 4.50*7 = $31.50
Let's denote the number of weeks that Rina has saved as x.
Rina saves $4.50 each week, so the total amount she has saved after x weeks is 4.50 * x = 4.5x.
Rina's sister saves $2 more each week, so after x weeks, Rina's sister has saved 4.5x + $2x = 6.5x.
We know that when her sister has saved $14 more than Rina, we can set up the equation:
6.5x = 4.5x + $14.
To solve for x, we can subtract 4.5x from both sides of the equation:
2x = $14.
Then we divide both sides of the equation by 2:
x = $14 / 2.
So, after x weeks, Rina has saved $7.
Therefore, Rina has saved $7.
To find out how much Rina has saved, we can set up an equation based on the given information. Let's call the amount of money Rina has saved 'R' and the amount her sister has saved 'S'.
We know that Rina saves $4.50 each week, so her savings can be represented as 4.5n, where 'n' is the number of weeks. Her sister saves $2 more each week, so her savings can be represented as (4.5 + 2)n = 6.5n.
According to the question, when her sister has saved $14 more than Rina, we can set up the equation:
S = R + 14
Substituting the expressions for R and S, we have:
6.5n = 4.5n + 14
Now we can solve for n:
6.5n - 4.5n = 14
2n = 14
n = 14 / 2
n = 7
So, it takes 7 weeks for Rina's sister to save $14 more than Rina.
To find out how much Rina has saved, we can substitute the value of n back into the expression for Rina's savings:
R = 4.5n
R = 4.5 * 7
R = 31.5
Therefore, Rina has saved $31.50.