Govt Exams
Advertisement
Topics in Quantitative Aptitude
Q.401
Easy
Compound Interest
Raj invested ₹12,000 at 8% per annum compound interest. What will be the amount after 2 years?
Correct Answer:
A. ₹13,996.80
EXPLANATION
Step 1: Use compound interest formula A = P(1 + r/100)^n.
Step 2: A = 12000(1 + 8/100)^2 = 12000(1.08)^2 = 12000 × 1.1664 = 13,996.80.
Step 3: The amount after 2 years is ₹13,996.80.
Priya borrowed ₹8,000 from a moneylender at 15% simple interest per annum. If she paid ₹3,600 as interest, for how long did she borrow the money?
Correct Answer:
C. 3 years
EXPLANATION
Using SI = (P × R × T) / 100, we have 3,600 = (8,000 × 15 × T) / 100.
Step 1: 3,600 = 1,200T.
Step 2: T = 3,600 / 1,200 = 3 years.
Option C is correct.
In how many years will ₹3,600 amount to ₹4,392 at 11% simple interest per annum?
Correct Answer:
A. 2 years
EXPLANATION
Step 1: Interest = 4,392 - 3,600 = ₹792.
Step 2: Using SI = (P × R × T) / 100, we get 792 = (3,600 × 11 × T) / 100.
Step 3: 792 = 396T, so T = 2 years.
Option A is correct.
At what rate of simple interest per annum will ₹2,400 become ₹2,928 in 2 years?
Correct Answer:
B. 11% p.a.
EXPLANATION
Step 1: Interest = 2,928 - 2,400 = ₹528.
Step 2: Using SI = (P × R × T) / 100, we get 528 = (2,400 × R × 2) / 100.
Step 3: 528 = 48R, so R = 11% p.a.
Option B is correct.
A shopkeeper sells pens at ₹12 each, making a profit of 50%. How much does he spend to buy 180 pens?
Correct Answer:
A. ₹1,440
EXPLANATION
Step 1: SP = ₹12, Profit = 50%, so CP = 12/1.50 = ₹8 per pen.
Step 2: Cost for 180 pens = 8 × 180 = ₹1,440.
So option A is correct.
If a watch is sold for ₹1,650 at a loss of 12%, what is its cost price?
Correct Answer:
A. ₹1,875
EXPLANATION
Step 1: Loss = 12%, so SP = 88% of CP.
Step 2: Let CP = x, then 0.88x = 1650.
Step 3: x = 1650/0.88 = ₹1,875.
So option A is correct.
A bookstore purchases novels at ₹240 per unit and sells them at ₹288 per unit. What is the profit percentage?
Correct Answer:
B. 20%
EXPLANATION
Step 1: Cost Price (CP) = ₹240, Selling Price (SP) = ₹288.
Step 2: Profit = SP - CP = 288 - 240 = ₹48.
Step 3: Profit% = (Profit/CP) × 100 = (48/240) × 100 = 20%.
So option B is correct.
If a merchant sells rice at ₹56 per kg and makes a profit of 40%, at what price did he buy the rice?
Correct Answer:
C. ₹40 per kg
EXPLANATION
Step 1: Selling Price = ₹56 per kg and Profit = 40%.
Step 2: CP = SP / (1 + Profit%/100) = 56 / 1.40 = ₹40 per kg.
Step 3: Verification: Profit = 40 × 0.40 = ₹16; SP = 40 + 16 = ₹56 ✓.
So option C is correct.
A mobile phone is sold for ₹18,900 at a profit of 35%. What is its cost price?
Correct Answer:
B. ₹14,000
EXPLANATION
Step 1: Selling Price = ₹18,900 and Profit = 35%.
Step 2: CP = SP / (1 + Profit%/100) = 18,900 / 1.35 = ₹14,000.
Step 3: Verification: Profit = 14,000 × 0.35 = ₹4,900; SP = 14,000 + 4,900 = ₹18,900 ✓.
So option B is correct.
If an article costs ₹640 and is sold at a loss of 8%, what is the selling price?
Correct Answer:
B. ₹588.80
EXPLANATION
Step 1: Cost Price = ₹640.
Step 2: Loss = 8% of 640 = 0.08 × 640 = ₹51.20.
Step 3: Selling Price = CP - Loss = 640 - 51.20 = ₹588.80.
So option B is correct.