Simple and Compound Interest Questions and Answers

Let us assume the years as x

SI = \frac{P\times N\times R}{100}

Initial amount = 1500

Amount after simple interest = 15000

Therefore, interest = 15000 – 1500 = 13500

Taking time T as x

Thus, 13500 = \frac{1500\times x\times 15}{100}

1350000 = 22500x

x = 1350000/22500 = 60 Years

Interest on Rs. 4000 at 8% = (8/100) * 4000 = Rs. 320 Interest on Rs. 8000 at 7.5% = (7.5/100) * 8000 = Rs. 600 Interest on Rs. 2800 at 8.5% = (8.5/100) * 2800 = Rs. 238

Total interest received on these amounts = Rs. 320 + Rs. 600 + Rs. 238 = Rs. 1158

Now, let's calculate the remaining amount:

Remaining amount = Rs. 20000 - Rs. 4000 - Rs. 8000 - Rs. 2800 = Rs. 5200

We know that the annual average interest received by Ashish is 8.13%. To find the interest on the remaining amount, we can set up the following equation:

(1158 + Interest on the remaining amount) / 20000 = 8.13/100

Let's solve for the interest on the remaining amount:

1158 + Interest on the remaining amount = (8.13/100) * 20000

1158 + Interest on the remaining amount = 1626

Interest on the remaining amount = 1626 - 1158 = 468

Now, let's calculate the percentage of interest received on the remaining amount:

Percentage of interest on the remaining amount = (468 / 5200) * 100

Percentage of interest on the remaining amount = 9%

Let us assume the rate as r% per annum.

Then, \frac{7000\times r\times 2}{100} + \frac{5000\times r\times 4}{100}

140r + 200r = 3060

r = \frac{3060}{340} = 9

Rate = 9%.

Let us assume the rate as r%.

Given, new interest rate = 2r%.

Given, the rate for 1 year

And, new rate = 4 months or 1/3  year(s).

Therefore, 1725 * r * 1 / 100 + 1362.5 * 2r * 1 / 100*3 = 133.5

= (5175 + 2725)r = 133.5 * 300

= 7900r = 40050

r = 40050/7900 = 5.06

Therefore, the original rate = 5.06%

Amount = 100 * 5400  / 15 * 5

= 540000 / 75

= 7200

Let us assume the years as x

SI = PxNxR/100,

Initial amount = 1375

Amount after simple interest = 20000

Therefore, interest = 20000 – 1375 = 18625

Thus, 18625 = 1375 * x * 15 /100

1862500 = 20625x

x = 1862500/20625 = 90. 3 Years

Extra amount invested by a person (605 – 550)= Rs.55
so the additional interest he earned on F.D = Rs.55

The first year interest=550/2=275rs.

Rate of interest=55/275*100=20%

20% interest means the person received 20% of the amount he invested in the F.D.

Now clearly if in one fixed deposit his 20% of his investment= Rs.275,

So his total investment = 275/20*100=1375. Thus his total saving before investment=2*1375=2750 rs.

Simple interest for one year = (1954 - 1800) = 154.

Simple interest for 5 years = (154 x 5) = 770.

Principal amount = (1800 - 770) = 1030

The amount is calculated as P(1 + RT)

Here P = ?, R = 5% Per Annum, T = 4 Years, S.I = 5016.25

S.I = \frac{P\times R\times T}{100}

5016.25 = \frac{P\times 5\times 4}{100}

\frac{5016.25\times 100}{20} = P

P = 25081.25

Now calculating the amount

A = P(1 + RT)

A = 25081.25\left ( 1 + \frac{5}{100}4\right )

on solving the above equation we get,

A = Rs. 30,097.5

t= (SI×100) /PR

=>t = (1050×100)/(3500×6) = 5

Now, the rate of interest of rs. 1800 on rs. 4500 for 5 years be 'r'

So, r = (1800×100)/(4500×5) = 8%