Simple interest
- A person lends 40% of his sum of money at 15% per annum, 50% of rest at 10% per annum and the rest at 18% per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum ?
-
View Hint View Answer Discuss in Forum
Let the person have ₹ 100.
ThenSI for 1 year = ₹ 
40 × 15 × 1 + 30 × 10 × 1 + 30 × 18 × 1 
100 100 100
Correct Option: C
Let the person have ₹ 100.
ThenSI for 1 year = ₹ 40 × 15 × 1 + 30 × 10 × 1 + 30 × 18 × 1 100 100 100
SI for 1 year = ₹ (6 + 3 + 5.4) = ₹ 14.4
∴ Rate of interest on whole sum = 14.4%
- The effective annual rate of interest, corresponding to a nominal rate of 6% per annum payable half yearly, is :
-
View Hint View Answer Discuss in Forum
Let the sum be ₹ 100.
For initial six months,Simple Interest = 100 × 6 × 6 = 3% 100 12
Now, sum = 100 + 3 = ₹ 103
For another six months,
Correct Option: D
Let the sum be ₹ 100.
For initial six months,Simple Interest = 100 × 6 × 6 = 3% 100 12
Now, sum = 100 + 3 = ₹ 103
For another six months,Simple Interest = 103 × 6 × 6 = 3.09 100 12
∴ Rate of interest per annum = 3 + 3.09 = 6.09%
- A sum of ₹ 1000 is lent out partly at 8% and the remaining at 10% per annum. If the yearly income on the average is 9.2%, the two parts respectively are
-
View Hint View Answer Discuss in Forum
Let p be lent on 8%.
∴ (1000 – p ) is lent on 10%.
Simple Interest = 9.2% of 1000 = ₹ 92SI = P × R × T 100 ∴ 92 = p × 8 + (1000 - p) × 10 100 100
Correct Option: A
Let p be lent on 8%.
∴ (1000 – p ) is lent on 10%.
Simple Interest = 9.2% of 1000 = ₹ 92SI = P × R × T 100 ∴ 92 = p × 8 + (1000 - p) × 10 100 100
⇒ 8p + 10000 – 10p = 9200
⇒ – 2p = 9200 – 10000
⇒ p = 800 ÷ 2 = ₹ 400 = First part
∴ Second part = ₹ 600
- The amount 2,100 became ₹2,352 in 2 years at simple interest. If the interest rate is decreased by 1%, what is the new interest ?
-
View Hint View Answer Discuss in Forum
As per the given in question ,
S.I. = Amount - Principal = 2352 – 2100 = ₹ 252Rate = Interest × 100 Principal × Time Rate = 252 × 100 = 6% per annum 2100 × 2
New rate = 5%
Correct Option: A
As per the given in question ,
S.I. = Amount - Principal = 2352 – 2100 = ₹ 252Rate = Interest × 100 Principal × Time Rate = 252 × 100 = 6% per annum 2100 × 2
New rate = 5%∴ S.I. = 252 × 5 = ₹ 210 6
- ₹800 amounts to ₹920 in 3 years at simple interest. If the interest rate is increased by 3%, it would amount to
-
View Hint View Answer Discuss in Forum
Given that , Amount = ₹ 920 and Principal = ₹ 800
∴ S.I. = Amount - Principal = ₹ (920 – 800) = ₹ 120∴ Rate = Interest × 100 Principal × Time Rate = 120 × 100 = 5% per annum 800 × 3
New rate = 8% per annum
Correct Option: D
Given that , Amount = ₹ 920 and Principal = ₹ 800
∴ S.I. = Amount - Principal = ₹ (920 – 800) = ₹ 120∴ Rate = Interest × 100 Principal × Time Rate = 120 × 100 = 5% per annum 800 × 3
New rate = 8% per annum∴ SI = 800 × 8 × 3 = ₹ 192 100
∴ Amount = Principal + SI = (800 + 192) = ₹ 992
