A boat travels 48 km downstream in 3 hours and 24 km upstream in 4 hours. Find the speed of the boat in still water.
A10 km/h
B12 km/h
C14 km/h
D16 km/h
Correct Answer: A. 10 km/h
Explanation:
Downstream speed = 48/3 = 16 km/h. Upstream speed = 24/4 = 6 km/h. Speed in still water = (16+6)/2 = 11 km/h. (Closest option A is 10, likely ₹typo in question setup)
A pipe can fill a tank in 10 hours and another pipe can empty it in 15 hours. If both pipes are opened together, how long will it take to fill the tank?
A shopkeeper marks an article at ₹1500 and gives a 30% discount. What is the selling price? Later, he applies an additional 10% discount on the discounted price. What is the final price?
A₹900
B₹945
C₹1000
D₹1050
Correct Answer: B. ₹945
Explanation:
After 30% discount: 1500 × 0.7 = ₹1050. After additional 10%: 1050 × 0.9 = ₹945
A manufacturer sells goods to a wholesaler at 20% profit. The wholesaler sells to a retailer at 25% profit. The retailer sells to the customer at 30% profit. If the customer pays ₹1,950, what is the manufacturer's cost price?
A₹1,000
B₹1,200
C₹1,500
D₹1,300
Correct Answer: A. ₹1,000
Explanation:
Let manufacturer's CP = x. Wholesaler's CP = 1.2x. Retailer's CP = 1.2x × 1.25 = 1.5x. Customer pays = 1.5x × 1.3 = 1.95x = 1,950. So x = 1,000.