- A lent Rs. 6000 to B for 3 years and Rs. 7000 to C for 4 years on simple interest at the same rate of interest and received Rs. 4600 in all from both of them as interest. The rate of interest per annum is:
12%10%8%9%NoneOption B

Solution:

Let the rate of interest be r.

(6000*r*3)/100 +(7000*r*4)/100=4600

180r+280r=4600

460r=4600==>r=10%.

- A certain amount earns simple interest of Rs. 1950 after 6 years. Had the interest been 3% more, how much more interest would it have earned?
Rs55Rs62Rs80Data InadequateNoneOption D

Solution:

Data Inadequate.

- A person borrows Rs. 6000 for 2 years at 6% p.a. simple interest. He immediately lends it to another person at 7 3/5 p.a for 2 years. Find his gain in the transaction per year.
Rs192Rs156Rs86Rs95NoneOption C

Solution: For 2years the gain is

(6000*38*2)/100*5 –(6000*6*2)/100

912-720=Rs192.

Then for 1 year 192/2=Rs86.

- Find the compound interest on Rs. 1000 at the rate of 20% per annum for 18 month when interest is compounded half yearly.
Rs662Rs545Rs620Rs568NoneOption A

Solution:

Principal, P = Rs. 2000

Compound rate, R = 20% per annum = 20/2 = 10% half-yearly

Time = 18 month = 3 half-years

Amount,

A = {P*[1+ (R/100)]^{n}}

= {2000*[1+(10/100)]^{3}}

= {(2000*11*11*11/10*10*10)}

A = Rs. 2662

compound interest = Rs. 662.

- A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?
2.5%3.46%4.25%3.5%NoneOption B

Solution:

Let rate of interest be r. New r =2r, n=1/3years(4month)

(725*r*1)/100 + (362.5*2r*1)/100*3 = 33.50

(2175+725)r=33.5*100*3

2900r=10050

R=3.46%. - What is the rate of simple interest for the first 4 years if the sum of Rs. 360 becomes Rs. 540 in 9 years and the rate of interest for the last 5 years is 6%?
4%10%8%5%NoneOption D

Solution:

Interest for the last 5 years = PTR/100;

= 360*5*6/100 = Rs. 108.

Interest for year = 540-360 = 180;

So, interest for first four years = 180-108 = Rs. 72;

Now, rate for first four years = (72*100)/360*4;

= 5%. - In what time will the simple interest on Rs. 1000 at 3% per annum be the same as that on Rs. 1500 at 6% per annum in 3 years?
6years8years9years5yearsNoneOption C

Solution:

Let time is n years.

(1000*3*n)/100 = (1500*6*3)/100

n=9years.

- Krish invested an amount of Rs. 6000 in a fixed deposit scheme for 2 years at compound interest rate 5 %p.a. How much amount will Krish get on maturity of the fixed deposit?
Rs6615Rs6540Rs6872Rs5875NoneOption A

Solution:

Amount=6000*(1+5/100)^{2}

=6000*21/20*21/20

=Rs 6615.

- A sum of money placed at compound interest doubles itself in 4 years. In how many years will it amount to 8 times?
10years12years8years9yearsNoneOption B

Solution:

x becomes 2x in 4years

Then x becomes 8x in ?

2x…………………… 4

8x(2*2*2)……….. ?

2x………………….. 4

2^{3}…….. ?

Short cut=multiply years with power=4*3=12years.

- Divide Rs. 6000 into two parts so that simple interest on the first part for 2 years at 6% p.a. may be equal to the simple interest on the second part for 3 years at 8% p.a.
Rs4000,Rs2000Rs3500,Rs2500Rs2300,Rs3700Rs3200,Rs2800NoneOption A

Solution:

Let 1st part be x and 2nd part be 6000-x.

(X*2*6/100) = ((6000-x)*3*8)/100

12x = 144000- 24x

36x = 144000

x = 144000/36 = Rs. 4000.

1st part = Rs. 4000

2nd part = Rs. 2000.

GOOD HELP

madam please chake question no 4. principle in question is 1000 but in solution 2000