Entrance Exams
Govt. Exams
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Topics in Quantitative Aptitude
Three successive discounts of 10%, 20%, and 30% are equivalent to a single discount of:
Correct Answer:
A. 49.6%
EXPLANATION
Final price = 100 × 0.9 × 0.8 × 0.7 = 50.4. Discount = 49.6%.
A shopkeeper bought goods for Rs. 5000 and sold at a profit of 20%. What is the selling price?
Correct Answer:
B. Rs. 6000
EXPLANATION
SP = 5000 + 20% of 5000 = 5000 + 1000 = 6000.
Two workers A and B can complete a job in 8 days and 12 days respectively. In how many days can they complete it working together?
Correct Answer:
A. 4.8 days
EXPLANATION
Combined rate = 1/8 + 1/12 = 5/24. Time = 24/5 = 4.8 days.
A man earns Rs. 500 more per month than a woman. If together they earn Rs. 4500 per month, how much does the man earn?
Correct Answer:
C. Rs. 2500
EXPLANATION
Let woman's salary = x. Man's salary = x + 500. x + x + 500 = 4500. x = 2000. Man earns Rs. 2500.
If the price of rice increases by 25%, by what percentage should consumption decrease to keep expenditure constant?
Correct Answer:
B. 20%
EXPLANATION
Let original price = 100, consumption = 100. New price = 125. For constant expenditure, consumption = 10000/125 = 80. Decrease = 20%.
Simple interest on Rs. 8000 at 12% per annum for 2.5 years is:
Correct Answer:
A. Rs. 2400
EXPLANATION
SI = (8000 × 12 × 2.5)/100 = 2400.
A boat travels 48 km upstream in 6 hours and 48 km downstream in 4 hours. What is the speed of the boat in still water?
Correct Answer:
B. 10 km/h
EXPLANATION
Upstream speed = 8 km/h, Downstream speed = 12 km/h. Boat speed = (8+12)/2 = 10 km/h.
Pipe A can empty a full tank in 12 hours. Pipe B can fill the same tank in 18 hours. If both pipes are opened simultaneously with the tank full, how long to empty it?
Correct Answer:
B. 36 hours
EXPLANATION
Net rate = 1/12 - 1/18 = 3/36 - 2/36 = 1/36. Time = 36 hours.
A train 150m long crosses a pole in 15 seconds. What is its speed in km/h?
Correct Answer:
A. 36 km/h
EXPLANATION
Speed = 150/15 = 10 m/s = 10 × 3.6 = 36 km/h.
Two pipes A and B can fill a tank in 20 hours and 30 hours respectively. If both pipes are opened together, how long will it take to fill the tank?
Correct Answer:
B. 12 hours
EXPLANATION
Combined rate = 1/20 + 1/30 = 5/60 = 1/12. Time = 12 hours.