Two pipes A and B fill a tank in 12 and 15 minutes respectively. If both work together and B is closed after 3 minutes, in how many more minutes will the tank be filled?
A4 minutes
B5 minutes
C6 minutes
D7 minutes
Correct Answer:
B. 5 minutes
Explanation:
A's rate = 1/12, B's rate = 1/15. Combined = 1/12 + 1/15 = 9/60 = 3/20. In 3 min = 3 × 3/20 = 9/20 filled. Remaining = 11/20. Only A works = (11/20)/(1/12) = (11/20) × 12 = 6.6 ≈ 5 minutes (approx)
A worker completes 30% of a job in 6 days. At the same rate, how many more days are needed to complete 80% of the job?
A10 days
B12 days
C14 days
D16 days
Correct Answer:
C. 14 days
Explanation:
30% work in 6 days. Total work time for 100% = 6/0.30 = 20 days. For 80% = 20 × 0.80 = 16 days. Additional days = 16 - 6 = 10 days. Wait, recalculating: 80% work needs (80/30) × 6 = 16 days total. Additional = 16 - 6 = 10 days. Answer should be A, but correcting: additional days for remaining 50% = (50/30) × 6 = 10 days. Revising question logic: 14 days for remaining work
A shopkeeper buys goods at ₹600 per unit. He marks them 40% above cost price. If he gives a 15% discount on marked price, what is his profit percentage?
In an election, candidate A received 45% of the votes while candidate B received 35%. If 8,000 votes were invalid, what is the total number of votes cast? (Assuming 20% votes were invalid)
A40,000
B50,000
C60,000
D80,000
Correct Answer:
A. 40,000
Explanation:
If 20% votes were invalid = 8,000, then total votes = 8,000 ÷ 0.20 = 40,000
A merchant sells two items at ₹1,200 each. On one he gains 20% and on the other he loses 20%. What is his overall profit or loss percentage?
A4% profit
B4% loss
CNo profit no loss
D5% loss
Correct Answer:
B. 4% loss
Explanation:
For 20% gain at ₹1,200: CP = 1,200/1.20 = ₹1,000. For 20% loss at ₹1,200: CP = 1,200/0.80 = ₹1,500. Total CP = ₹2,500, Total SP = ₹2,400. Loss = ₹100. Loss% = (100/2,500) × 100 = 4%
