Principal = Rs. 100 x 4016.25 9 x 5 = Rs. 401625 45 = Rs. 8925.

Answer : Option C

Explanation :

Let the the sum of money(P) be Rs.x
Time(T) = 3 ¹â„₈ Years = ²⁵⁄₈ Years
Simple interest (SI) = ^x⁄₄
$MF#%\text{Rate of interest per annum(R) = }\dfrac{100 \times \text{SI}}{\text{PT}} = \dfrac{100 \times \dfrac{x}{4}}{x \times \dfrac{25}{8}} = \dfrac{100 \times x \times 8}{4 \times x \times 25} = 8\%$MF#%

Answer : Option D

Explanation :

Let the rate of interest per annum be R%
Simple Interest for Rs.4000 for 2 years at R% + Simple Interest for Rs.2000 for 4 years at R%
= 2200
$MF#%\begin{align}&\dfrac{4000 \times \text{R} \times 2}{100} + \dfrac{2000 \times \text{R} \times 4}{100} = 2200\\\\ &80\text{R} + 80 \text{R} = 2200\\\\ &160\text{R} = 2200\\\\ &16\text{R} = 220\\\\ &4\text{R} = 55\\\\ &\text{R} = \dfrac{55}{4} = 13.75\% \end{align}$MF#%

Answer : Option D

Explanation :

Principal(P) = ?
Time(T) = 4 years
Simple Interest(SI) = Rs.6200
R = 8%
$MF#%\text{P = }\dfrac{100 \times \text{SI}}{\text{RT}} = \dfrac{100 \times 6200}{8 \times 4} = \text{Rs.}19375$MF#%

Let sum be Rs. x then , S.I.=Rs.(x*(27/2) *4*(1/100) ) = Rs.27x/50
amount = (Rs. x+(27x/50)) = Rs.77x/50
77x/50 = 2502.50
x = (2502.50 * 50)/77 = 1625
Hence , sum = Rs.1625.

Answer : Option D

Explanation :

Since we do not have the principal and rate of interest, we can not find out the required details.

Let the sum be Rs. 100. Then,

S.I. for first 6 months = Rs. 100 x 10 x 1 = Rs. 5 100 x 2

S.I. for last 6 months = Rs. 105 x 10 x 1 = Rs. 5.25 100 x 2

So, amount at the end of 1 year = Rs. (100 + 5 + 5.25) = Rs. 110.25

Effective rate = (110.25 - 100) = 10.25%

Answer : Option B

Explanation :

Time from May 3rd to July 15th = 28 days of May + 30 days of June and 15 days of July
$MF#%\text{= 73 days= }\dfrac{73}{365}\text{ years = }\dfrac{1}{5}\text{ years}$MF#%
$MF#%\text{Simple interest = }\dfrac{\text{PRT}}{100}= \dfrac{500 \times 6 \times \dfrac{1}{5}}{100} =
6$MF#%

Answer : Option D

Explanation :

$MF#%\text{Simple Interest, SI = }\dfrac{\text{PRT}}{100}$MF#%
i.e, SI ∝ T when rate(R) and principal (P) are constants
Let x be the sum of money and which will treble in n years
(Please note that when the money doubles, simple interest is 2x - x = x
and when the money trebles, simple interest is 3x - x = 2x)
(2x-x) ∝ 12
=> x ∝ 12 -------------(1)
(3x-x) ∝ n
=> 2x ∝ n -------------(2)
From (1) and (2),
$MF#%\dfrac{x}{2x} = \dfrac{12}{n}\\\\ \dfrac{1}{2} = \dfrac{12}{n}\\\\ \Rightarrow \text{n = 24 years}$MF#%
i.e, in 24 years, the money will treble.

Answer : Option C

Explanation :

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Solution 1
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$MF#%\text{Principal, P = }\dfrac{100 \times \text{SI}}{\text{RT}} = \dfrac{100 \times 101.20}{5 \times 1}= 20 \times 101.20 = \text{Rs. 2024}\\\\ \text{Simple Interest for Rs.2024 at 6% per annum for 1 year, SI = }\dfrac{2024 \times 6 \times 1}{100} = 121.44$MF#%
Additional Interest = Rs.121.44 - Rs.101.20 = Rs.20.24
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Solution 2
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$MF#%\text{Principal, P = }\dfrac{100 \times \text{SI}}{\text{RT}} = \dfrac{100 \times 101.20}{5 \times 1}= 20 \times 101.20 = \text{Rs. 2024}$MF#%
All parameters remains same except the increase in interest rate.
and additional Interest Rate = 6% - 5% = 1%
$MF#%\text{Hence, Additional Interest = Simple Interest for Rs.2024 at 1% per annum for 1 year}\\\\=\dfrac{2024 \times 1 \times 1}{100} = 20.24$MF#%