Question

a sum doubles in 20yrs at certain rate of int. in how many years the sum will triple at the SAme rate of int? ​

Answer 1

Answer:

1

A sum of money doubles in 20 years at simple interest, in how many years will it triple?

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Any Individual who desires to open savings bank account in individual capacity need to furnish following documents:- 1. Permanent

Cole Nikol

Answered November 13, 2017

If it doubles in 20 years, you’ll get triple after 30 years. Why?

Example: you start with 1000$.

It will take 20 years to double the base amount: 1000 * 5% a year = 1050 at the end of each year.

1000 / 50 = 20 years

on year 20, you’ll have the base (1000$) + interest for the last 20 years (1000$) = 2000$ total

Now when you have 2000$ as a basic amount you’ll need half the time to get another 1000$ at 5% per year rate:

2000$ * 5% a year = 2100$ at the end of a year (100$ plus)

you’ll need only 1000$/100 = 10 years to get additional 1000$

or in other words to get 3000$ you’ll need 30 years to triple your invested amount at a rate of 5% per year

Actually, this goes less than 30 years as the actual bank rates are calculated differently (interest is added to a basic amount and this is the base to coalculate for the next year and so on). Please check the actual calculator