1. If the simple interest on a certain sum of money for 4 years is one–fifth of the sum, then the rate of interest per annum is

1. 4%

2. 7%

3. 6%

4. 5%

Answer & Explanation

Answer:- 4

Explanation :-

Let the sum of money be x

Therefore SI = x/5

T = 4 years

R = (SI*100) / (P*T) = ((x/5)*100)/(x*4)

=>5%

2. A certain sum in invested for T years. It amounts to Rs. 400 at 10% per annum. But when invested at 4% per annum, it amounts to Rs. 200. Find the time (T).

1. 45 years

2. 60 years

3. 40 years

4. 50 Years

Answer & Explanation

Answer:- 4

Explanation :-

Let P be The principal , A as Amount

Therefore ,

Time (T) ={(A1 -A2)/[(A1*R2)-(A2R1)]}*100

=> (400-200)/[(200*10)-(400*5)]*100

=> 20000/400 = 50 Years

3. A sum of money is lent at S.I. for 6 years. If the same amount is paid at 4% higher, Arun would have got Rs. 120 more. Find the principal

1. Rs. 200

2. Rs. 600

3. Rs. 400

4. Rs. 500

Answer & Explanation

Answer:- 4

Explanation :-

SI at 4% for Principal is Rs.120

Therefore ,

P = (120*100)/(4*6)

P = Rs. 500

4. Mr. Mani invested an amount of Rs. 12000 at the simple interest rate of 10% per annum and another amount at the simple interest rate of 20% per annum. The total interest earned at the end of one year on the total amount invested became 14% per annum. Find the total amount invested.

1. Rs. 25000

2. Rs. 15000

3. Rs. 10000

4. Rs. 20000

Answer & Explanation

Answer:- 4

Explanation :-

SI(1) = 12000*10*1/100 = 1200

SI(2) = (P*20*1)/100 = P/5

Total SI = 1200 + (P/5)

Therefore ,

1200 + (P/5) is the SI for Rs.(12000 + P) at 14% p.a. for 1 year

1200 + (P/5) = [(12000 + P)*14*1]/100

120000 + 20P = 14*12000+14P

6P = 14*12000 − 120000

6P = 48000 P = Rs. 800

Total amount invested = 12000 + P = 12000 + 8000 = Rs. 20000

5. A lent Rs. 4000 to B for 2 years and Rs. 2000 to C for 4 years on simple interest at the same rate of interest and received Rs. 2200 in all from both of them as interest. The rate of interest per annum is :

1. 14%

2. 15%

3. 12%

4. 13.75%

Answer & Explanation

Answer:- 4

Explanation :-

According to statement

Total SI = Rs. 2200

SI for Rs.4000 for 2 years + SI for Rs.2000 for 4 years at = 2200

As Rate of Interest is same for both The Principals

[(4000*R*2)/100] + [(2000*R*4)/100] = 2200

80R + 80R = 2200

160R = 2200

R = 13.75%