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Q71.

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Precalculus Mathematics for Calculus

Found in: Page 690

Book edition 7th Edition

Author(s) James Stewart, Lothar Redlin, Saleem Watson

Pages 948 pages

ISBN 9781337067508

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Short Answer

A woman invests a total of $20,000 in two
accounts, one paying 5% and the other paying 8% simple
interest per year. Her annual interest is $1180. How much did
she invest at each rate?

For the given investment problem the woman invested $14,000 at a rate of 5% and $6,000 at a rate of 8%.

See the step by step solution

Step by Step Solution

TABLE OF CONTENTS :

TABLE OF CONTENTS

Step 1. Given information.

x = the amount invested in the first account.

y = the amount invested in the second account.

Step 2. Write down the concept.

x + y = 20000 …….(1)

Also the total sum of interest earned would be,

0.05x + 0.08y = 1180 ……….(2)

Step 3. Determining the values

Solving equation (1) and (2) we have,

20 $\times$ equation (2) gives x + 1.6y = 23600

Now subtracting this to equation (1), we get

0.6y = 3600

y = 6000

Substituting this in (1)

x + 6000 = 20000

x = 14000

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