Question
The ratio of the speed of boats ‘A’ and ‘B’ in
still water is 8:9, respectively. The speed of the current is 25% of the speed of boat ‘A’ in still water. If boat ‘A’ takes 8 hours to travel 640 km downstream, then find the time taken by boat ‘B’ to travel 168 km upstream and 880 km downstream. (Note: Both the boats are rowing in the same stream.)Solution
Let the speeds of boats ‘A’ and ‘B’ in still water be 8x km/hr and 9x km/hr Therefore, speed of the current = 0.25 × 8x = 2x km/hr According to the question, 8x + 2x = 640/8 Or, 10x = 80 Or, x = 8 Therefore, upstream speed of boat ‘B’ = 9x – 2x = 7x = 56 km/hr Downstream speed of boat ‘B’ = 9x + 2x = 11x = 88 km/hr Required time taken = (168/56) + (880/88) = 3 + 10 = 13 hours
A coin is tossed. If head occurs, a ball is drawn from a bag containing 3 red and 4 green balls. If tail occurs, a die is thrown. The probability that t...
In the question, the given two series following the same pattern, then find the pattern used in the 1st series and use the pattern to find the unknown v...
The ratio of zinc and copper in a brass pieces is 2:5. How much zinc will be there in 140 kg of such a piece?
A person borrows ₹5000 at 12% per annum simple interest. He repays ₹3200 at the end of 2 years. How much does he still owe after 2 years?
120 litres of mixture contains water and milk in the ratio 5:6 respectively. If 32 litres of the mixture is replaced by same quantity of water, then fin...
?, 241, 308, 395, 506, 645
A circle with radius 5 units is inscribed in a square. What is the area of the square?
- Which numbering system consists of digits 0-9 and letters A-F?
