- A sum of rs.P invested on compound interest annually at certain rate of interest and it three times itself in five years. In how many years the amount to 9 times itself at the same rate of interest ?
5 years8 years7 years10 years12 yearsOption D

3P = P(1 + R/100)^5

3 = (1 + R/100)^5

3^2 = (1 + R/100)5*2

9 = (1 + R/100)^10

time = 10 years - A lends rs. 5500 to B at 20% per annum and B lends the same sum to C at 22% per annum. Find the gain of B after 2 years in simple interest.
380275220440554Option C

B gives the interest to A after 2 years,

5500 * 20/100 * 2 = 2200

C gives the interest to B after 2 years

5500 * 22/100 * 2 = 2420

the gain of B = 2420 – 2200 = 220 - Difference between compound interest and simple interest on sum of rs.4800 at certain rate of interest after 2 years is rs. 108. What is the rate of interest ?
14%15%17%12.5%24%Option B

CI – SI = PR^2/100^2

108 = 4800R^2/10000

R^2 = 108 * 10000/4800

P^2 = 225

R = 15% - After two years ratio between simple interest to principle is 2 : 5. If difference between CI and SI after two years is 208, then find principle ?
48004750454048505200Option E

Let principle = 5x

and SI = 2x

rate of interest for two years = 2x/5x * 100 = 40%

rate of interest for 1 years = 40%/2 = 20%

CI – SI = PR^2/100^2

208 = P (20)^2/10000

P = 5200 - Two persons P and Q invested rs. (x + 3400) and (x+ 2200) at the rate of 15% and 20% respectively for two years in simple interest. After two years total SI is rs.7220, then how much amount invested by Q ?
76009820584064509240Option A

(x + 3400) * 15 /100 * 2 + (x + 2200) * 20/100 * 2 =7220

(x + 3400) * 3/10 + (x+2200)*2/5 = 7220

(3x + 102000/10) + (2x + 4400/5) = 7220

(3x + 10200 + 4x + 8800/10) = 7220

7x + 19000 = 72200

x = 7600 - Total sum of rs.4740 is invested by two friends A and B in a scheme at the rate interest of 12% p.a for 4 year in SI. If interest received by B is 67.20 more than interest received by A, then find how much amount invested by A ?
2800230018402350none of theseOption B

A invested = x

B invested = 4740 – x

(4740 – x) 12/100 * 4 – x * 12/100 * 4 = 67.20

48/100 ( 4740 – x – x) = 6720

12/25 (4740 – 2x) = 67.20

4740 – 2x = 67.20 * 25/12

4740 – 2x = 140

2x = 4600

x = 2300

amount invests by A= 2300 - What is the compound interest accrued on a sum of 1400 at the rate of 6% in 2 years ?

184.25254.08334.05173.04234.14Option D

Compound interest for 2 years

6 + 6 + 6 * 6/100 = 12.36 %

compound interest = 1400 * 12.36/100 = 173.04 - The compound interest on a certain sum at 20% p.a for 2 years is rs. 98 more than the simple interest on same sum at 15% per annum for 2 years. What is the sum ?
7004803201000650Option A

Let sum is rs.x

compound interest for 2 years at 20 % p.a

20 + 20 + 20 * 20 /100 = 44%

simple interest for 2 years at 15 % = 15% * 2 = 30%

x * 44/100 – x * 30/100 = 98

x = 700 - A certain sum is deposited at rate of 40% p.a on Compound interest. Difference between interest earned at the 1st and 2nd year is rs.384. What is the sum ?
48004500320045002400Option E

Let sum = 100x

interest of 1st year = 100x * 40/100 = 40x

total amount at the end of the 1st year = 100x + 40x = 140x

interest of 2nd year = 140x * 40/100 = 56x

difference = 56x – 40x = 16x

16x = 384

x = 24

sum = 100x = 100 * 24 = 2400 - What is difference between the compound interest on rs.4000 for 1.5 years at 40% p.a compounded yearly and half-yearly ?
182192534314208Option B

Rate of interest after 1.5 years compounded yearly at 40%p.a

40 + 20 + 800/100 = 68%

CI = 4000 * 68/100 = 2720

Rate of interest after 1.5 years compounded half-yearly

rate of interest = 40/2 = 20%

20 + 20 + 20 * 20 /100 = 44%

44% + 20% + 880/100 = 72.80%

CI = 4000 * 72.80 /100 = 2912

difference = 2912 – 2720 = 192