Question

certain sum becomes 6400 rupees in 4 years and 8200 in 7 years at simple interest find the principal​

Answer 1

Answer:

4000 is your principal.

Step-by-step explanation:

this is just easy and can be solve orally.

so in 3 years is changes from 6400 to 8200 that means 8200-6400 =1800 so for every year it changes by 1800/3 =600

thus for start, in 4 years it becomes 6400. so for 4 years it would be 4*600=2400

so your principal would be 6400-2400=4000

and for your extra knowledge from principal that is 4000, the rate of interest per year is 15%

mark me as brainlist :)

Answer 2

Answer:

8200-6400=1800 for 3years

1800/3=600 for 1 year

600x4 = 2400 for 4 years

6400-2400= 4000/-

Principal = 4000/-