Question Detail
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
1. Reema took a loan of Rs 1200 with simple interest for as many years as the rate of interest. If she paid Rs. 432 as interest at the end of the loan period, what was the rate of interest.
- 5%
- 6%
- 7%
- 8%
Answer: Option B
Explanation:
Let rate = R% then Time = R years.
\begin{aligned}
=> \frac{1200*R*R}{100}=432 \\
=> R^2 = 36 \\
=> R = 6\%
\end{aligned}
2. 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
- 9%
- 10%
- 11%
- 12%
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%
3. In how many years Rs 150 will produce the same interest at 8% as Rs. 800 produce in 3 years at 9/2%
- 8
- 9
- 10
- 11
Answer: Option B
Explanation:
Clue:
Firstly we need to calculate the SI with prinical 800,Time 3 years and Rate 9/2%, it will be Rs. 108
Then we can get the Time as
Time = (100*108)/(150*8) = 9
4. Sachin borrows Rs. 5000 for 2 years at 4% p.a. simple interest. He immediately lends money to Rahul at 25/4% p.a. for 2 years. Find the gain of one year by Sachin.
- 110.50
- 111.50
- 112.50
- 113.50
Answer: Option C
Explanation:
Two things need to give attention in this question, First we need to calculate gain for 1 year only.
Second, where we take money at some interest and lends at other, then we use to subtract each other to get result in this type of question. Lets solve this Simple Interest question now.
\begin{aligned}
\text{Gain in 2 year = } \\
[(5000 \times \frac{25}{4} \times \frac{2}{100})-(\frac{5000 \times 4 \times 2}{100})] \\
= (625 - 400) = 225 \\
\text{ So gain for 1 year = }\\
\frac{225}{2} = 112.50
\end{aligned}
5. A financier claims to be lending money at simple interest, But he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes.
- 10.25%
- 10%
- 9.25%
- 9%
Answer: Option A
Explanation:
Let the sum is 100.
As financier includes interest every six months., then we will calculate SI for 6 months, then again for six months as below:
SI for first Six Months = (100*10*1)/(100*2) = Rs. 5
Important: now sum will become 100+5 = 105
SI for last Six Months = (105*10*1)/(100*2) = Rs. 5.25
So amount at the end of year will be (100+5+5.25)
= 110.25
Effective rate = 110.25 - 100 = 10.25