Directions: Study the following questions carefully and choose the right answer:
1
A certain amount earns simple interest of Rs. 1750 after 7 years. Had the interest been 2% more, how much more interest would it have earned ?
A. ₹ 35
B. ₹ 350
C. ₹ 245
D. Can't be determined
E. None of these
2
The Interest received at 15% per annum simple interest after 3 yrs is Rs. 630. What was the principal (in Rs)?
A. ₹ 1200
B. ₹ 1750
C. ₹ 1400
D. ₹ 2000
E.
None of these
3
A sum of money becomes 9 times in 20 years. Find the 10 times of rate of interest.
A. 350%
B. 45%
C. 400%
D. 250%
E. None of these
4
A sum becomes 6 fold at 5% per annum. At what rate, the sum becomes 12 fold?
A. 10%
B. 12%
C. 9%
D. 11%
E. None of these
5
The rates of simple interest in two banks x and y are in the ratio of 10 : 8. Rajini wants to deposit her total savings in two banks in such a way that she receives equal half-yearly interest from both. She should deposit the savings in banks x and y in the ratio of
A. 4 : 5
B. 3 : 5
C. 5 : 4
D. 2 : 1
E. None of these
6
The simple interest accrued on an amount of Rs. 12450 at the end of 6 years is Rs. 8964. What is the rate of interest per year?
A. 8%
B. 14%
C. 10%
D. 12%
E. None of these
7
The simple interest on a sum of money will be Rs. 600 after 10 years. If the principal is trebled after 5 years, what will be the total interest at the end of the tenth year?
A. ₹ 600
B. ₹ 900
C. ₹ 1200
D. ₹ 1500
E. None of these
8
According to a new plan rolled out by HISP Bank, the rate of simple interest on the sum of money is 8% pa for the first two years, 10% pa for the next three years and 6% pa for the period beyond the first five years. The simple interest accrued on a sum for a period of eight years is Rs. 12,800. Find the sum
A. ₹ 24000
B. ₹ 16000
C. ₹ 15000
D. ₹ 13500
E. None of these
9
A certain sum of money amounts to ₹ 720 in 2 years and ₹ 870 in 4.5 years. Find the sum and the rate of interest.
A. ₹ 600, 10%
B. ₹ 600, 12%
C. ₹ 620, 12%
D. ₹ 660, 12%
E. ₹ 620, 10%
10
₹ 16000 was invested for three years, partly in scheme A at the rate of 5% simple interest per annum and partly in scheme B at the rate of 8% simple interest per annum. The total interest received at the end was ₹ 3480. What amount of money was invested in scheme A ?
A. ₹ 6000
B. ₹ 6500
C. ₹ 4500
D. ₹ 4000
E. ₹ 8000
Question No. 1
Correct Option: D
Explanation:
When we solve this question, we find that we have two variables P (Principal) and R (Initial assumed rate of interest) in the R.H.S. of the SI equation. Therefore, the correct answer can't be determined.
Question No. 2
Correct Option: C
Explanation:
P = Rs. 1,400
Hence, Option C is correct.
Question No. 3
Correct Option: C
Explanation:
According to the formula,
= | 100(9 – 1) | = | 800 | = 40% |
20 | 20 |
∴ 10 times of 40% = 400%
Hence, option C is correct.
Question No. 4
Correct Option: D
Explanation:
Method I:Given, R1 = 5%, n = 6, m = 12
According to the formula,
= | 12 – 1 | × 5 = | 11 | × 5 = 11% |
6 – 1 | 5 |
Method II:
SI at 5% = 6P – P = 5P
⇒ T = 100 yr
Now, for new rate (R),
∴ R = 11%
Hence, option D is correct.
Question No. 5
Correct Option: A
Explanation:
Let the savings be P and Q and rates of SI be 10x and 8x, respectively.
Then, P × 10x × | 1 | × | 1 | = Q × 8x × | 1 | × | 1 |
2 | 100 | 2 | 100 |
⇒ 10P = 80
∴ | P | = | 8 | = | 4 |
Q | 10 | 5 |
∴ P : Q = 4 : 5.
Hence, opiton A is correct.
Question No. 6
Correct Option: D
Explanation:
SI = 8964 and T = 6 yrs, P = 12450
Then, rate = | 8964 × 100 | = 12% |
12450 × 6 |
Hence, option D is correct.
Question No. 7
Correct Option: C
Explanation:
Given that
Simple interest for 10 years = ₹ 600
Therefore, SI for 1 year = ₹ 60
Therefore, SI for 5 years = ₹ 300
Now, if the principal is trebled, the interest will also be trebled.
Therefore, SI for next 5 years = ₹ 300 x 3 = ₹ 900
Hence, total interest after 10 years = 300 + 900 = ₹ 1200
Hence, option C is correct.
Question No. 8
Correct Option: E
Explanation:
Total rate of interest = (2 × 8 + 3 × 10 + 3 × 6)%
= (16 + 30 + 18)% = 64%
Let the sum be x, then
∴ 64% of x = 12800
x = | 12800 × 100 | = 20000/- |
64 |
Hence, option E is correct.
Question No. 9
Correct Option: A
Explanation:
Let the sum be P; the rate of interest be R.
Then, Amount = P + SI
720 = P + | P × R × 2 | ... (i) |
100 |
870 = P + | P × R × 4.5 | ...(ii) |
100 |
Eq. (ii) – (i),
⇒ PR = 6000 ...(iii)
Now, from eq (i),
⇒ P = 720 – 120 = ₹ 600
From eq. (iii),
600 × R = 6000
⇒ R = 10%
Hence, option A is correct.
Question No. 10
Correct Option: D
Explanation:
Let the sum invested in scheme A be ₹ x.
Then the amount invested in scheme B = ₹ (16000 – x)
Now, | x × 5 × 3 | + | (16000 – x) × 3 × 8 | = 3480 |
100 | 100 |
⇒ 15x + 384000 – 24x = 3480 × 100
⇒ 9x = 384000 – 348000 = 36000
Hence, option D is correct.