Question
A boat has a speed of 30 km/h in still water. In a
particular stream, the boat's downstream speed is 50% faster than its speed upstream. What is the speed of the stream?Solution
Let the speed of the stream = 'k' km/h Then, upstream and downstream, speed of the boat are (30 - k) km/h and (30 + k) km/h, respectively According to the question, 30 + k = (30 - k) X 1.5 Or, 30 + k = 45 - 1.5k Or, 2.5k = 15 So, k = 6 Therefore, speed of the stream = 6 km/h
11, 9, 15, 41 ,157, 789
81, 90, 108, 135, 171, ?
12, 16, 25, 41, 66, ?
729 512 343 216 125 ?
...19.11 × 5.98 + 20.03 × 3.12 – 34.95 + 97.9 × 3.02 =?
2, 17, 147, 1167, 8157, 48957
92,  51,  21,  13.5,  x,  4.25
find the value of (10x + x -5)?
25 13.5 12.5 20.75 39.5 ? 302.25
...5, 14, 41, 122, 365, 1094, ?
Find the missing term.
D – 4, F – 6, H – 8, J – 10, ?, ?