MATH SOLVE

5 months ago

Q:
# For 3 years I deposited my savings at Caja Arequipa, generating interest of S/. 1360 during those years, when I made the withdrawal of my savings plus interest it amounted to S/. 16,540. Calculate the annual interest rate.

Accepted Solution

A:

- You deposited savings for 3 years
- During those 3 years you earned interest of S/. 1360
- When you withdrew, your total amount was S/. 16,540
- Let's call your original savings amount S
- Then after 3 years:
\*\* Your original savings: S
\*\* Interest earned each year (at the same rate): r*S
\*\* Total after 3 years: S + 3*r\*S
- We're given:
\*\* Total withdrawn: S + 3*r*S = S/. 16,540
\*\* Total interest earned: 3*r*S = S/. 1360
- Set up two equations and solve for r:
\*\* S + 3*r*S = S/. 16,540
\*\* 3*r*S = S/. 1360
\*\* 3*r*S/S = 1360/S
\*\* r = 1360/3S = 0.08 = 8%
Therefore, the annual interest rate is 8%.