Question

a certain amount was deposited into the bank account having interest rate of 5 percent. if the total amount after 4 years was 1500 rupees, how much was the amount deposited initially?for the same initial amount, how should the interest rate increase such that the simple interest would amount to rupees 400

Answer 1

Step-by-step explanation:

r=5%

t=4 years

A=Rs. 1500

S.I.= P × R × T/ 100

S.I= A-P

1500- P = P × 5 × 4/ 100

1500- P = P/5

1500= P/5 + P

1500= 6P/5

1500×5/6 = P

P=Rs. 1250

S.I.2 =Rs. 400

r= ?

P=Rs. 1250

t= 4 years

r= 100 × si2/ P × t

r= 100 × 400 / 1250 × 4

r= 8%

now difference of rates= 8-5= 3

the initial rate should increase 3% to have si2 as Rs. 400.

Answer 2

3%...................................