Central Exam — Quantitative Aptitude
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Showing 161–170 of 429 questions
Q.161
Easy
Numbers
If the simple interest on Rs. 1000 for 2 years at rate R% per annum is Rs. 200, find the rate R.
Correct Answer:
C. 10%
Explanation:
SI = (P × R × T)/100. 200 = (1000 × R × 2)/100. R = 10%
Q.162
Easy
Numbers
A shopkeeper marks goods at 40% above cost price. If he gives a discount of 25%, what is his profit percentage?
Correct Answer:
A. 5%
Explanation:
Let CP = 100. MP = 140. After 25% discount, SP = 140 × 0.75 = 105. Profit = 5%.
Q.163
Easy
Numbers
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.
Q.164
Easy
Numbers
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.
Q.165
Easy
Numbers
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.
Q.166
Easy
Numbers
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.
Q.167
Easy
Numbers
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.
Q.168
Easy
Numbers
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%.
Q.169
Easy
Numbers
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.
Q.170
Easy
Numbers
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.