Question
The speed of a boat in still water is 26 km/hr. If the
boat covers 75 km in upstream in 5 hours, then find the time taken by the boat to travel 111 km in downstream.Solution
Let the speed of the boat in still water and the speed of the current be ‘x’ km/hr and ‘y’ km/hr, respectively Upstream speed of the boat = (x – y) = 75/5 = 15 km/hr Or, 26 – y = 15 Or, y = 26 – 15 = 11 km/hr Therefore, downstream speed of the boat = 26 + 11 = 37 km/hr Required time taken = 111/37 = 3 hours
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Find the variance of the numbers 13, 16, 22, 17.
The ratio of the angles of a quadrilateral is 3:2:7:8. What is the sum of the largest and the smallest angle?
