Question Detail

There was simple interest of Rs. 4016.25 on a principal amount at the rate of 9%p.a. in 5 years. Find the principal amount

Rs 7925
Rs 8925
Rs 7926
Rs 7925

Answer: Option B

Explanation:

\begin{aligned}
P = \frac{S.I. * 100}{R*T}
\end{aligned}

So by putting values from our question we can get the answer

\begin{aligned}
P = \frac{4016.25 * 100}{9*5} \\
= 8925
\end{aligned}

1. A sum of money amounts to Rs 9800 after 5 years and Rs 12005 after 8 years at the same rate of simple interest. The rate of interest per annum is

Answer: Option D

Explanation:

We can get SI of 3 years = 12005 - 9800 = 2205

SI for 5 years = (2205/3)*5 = 3675 [so that we can get principal amount after deducting SI]

Principal = 12005 - 3675 = 6125

So Rate = (100*3675)/(6125*5) = 12%

2. Find the simple interest on Rs 7000 at 50/3 % for 9 months

Rs. 1075
Rs. 975
Rs. 875
Rs. 775

Answer: Option C

Explanation:

\begin{aligned}
\text{ S.I. = } \frac{P \times R \times T}{100}
\end{aligned}
So, by putting the values in the above formula, our result will be.
\begin{aligned}
\text{ Required result = } \frac{7000 \times 50 \times 9}{3 \times 12 \times 100} = 875
\end{aligned}

[Please note that we have divided by 12 as we converted 9 months in a year format]

3. If a sum of money doubles itself in 8 years at simple interest, the ratepercent per annum is

12
12.5
13
13.5

Answer: Option B

Explanation:

Let sum = x then Simple Interest = x

Rate = (100 * x) / (x * 8) = 12.5

4. A sum of money at simple interest amounts to Rs. 2240 in 2 years and to Rs. 2600 in 5 years. What is the principal amount

1000
1500
2000
2500

Answer: Option C

Explanation:

SI for 3 year = 2600-2240 = 360
SI for 2 year 360/3 * 2 = 240
principal = 2240 - 240 = 2000

5. At what rate percent per annum will the simple interest on a sum of money be 2/5 of the amount in 10 years

Answer: Option D

Explanation:

Let sum = x
Time = 10 years.
S.I = 2x /5, [as per question]
Rate =( (100 * 2x) / (x*5*10))%
=> Rate = 4%