Question

Tina is saving to buy a notebook computer. She has two options. The first option is to put $300 away initially and save $10 every month The second option is to put $200 away initially and save $30 every month . After how many months would Tina save the same amount using either option ? How much would she save with either option ? After Box month , Tina will save with either option.

Answer 1

5 months, $350

Explanation:

Under option 1, where Tina starts with $300 and adds $10 per month, her savings after m months will be ...

300 +10m

Under option 2, where Tina starts with $200 and adds $30 per month, her savings after m months will be ...

200 +30m

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We want to find the value of m such that the two options produce the same result:

300 +10m = 200 +30m

100 = 20m . . . . . . . . . . . add -10m-200 to both sides of the equation

5 = m . . . . . . . . . . . divide by 20

Her savings balance after 5 months will be ...

300 +10(5) = 300 +50 = 350

After 5 months, Tina will save $350 with either option.