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Jill has $1275.00 in her savings account. When she opened her account, she had $300.
Every week she deposited $75.00. How many weeks did it take to earn $1275.00?
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As I see from your post, this bank does not give an interest, at all (zero interest rate).
So, the money grows only because she adds her saving each week.
At such conditions, the term "to earn" is not applicable, at all.
The term to use instead is "to save".
You may write this equation
1275 = 300 + 75*w
and solve it for w, the number of week.
You will get then w = = = 13 weeks. ANSWER
Solved.
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Memorize that the term "account earns" relates only to an interest.
It does not include the initial/original principal and/or the deposits.