Question
Speed of a boat in still water is 9 km/hr. It goes 12 km
downstream and comes back to the starting point in three hours. What is the speed of water in the stream?Solution
Let the speed of the boat = 9km/hr Speed of current = x km/hr Speed upstream = (9 – x) km/hr Speed downstream = (9 + x) km/hr Time upstream + time downstream = 3 hours Time  = distance/(speed ) 12/(9-x)+  12/(9+x) = 3 x = 3 km/hrÂ
What will come in the place of questions (?) mark in the following questions.
53, 55, 61, 71, 85, ?
√(10198 )× √(7220 )÷ 16.69 + 2010.375= ?
7, 7, 14, 40, ?, 227
24, 42, 60, ?, 96, 114
196, 196, 203, 229, 292, ?
500, 250, 750, 375, 1125, 562.5, ?
22, 37, 63, 98, 148, ?
What will come in the place of questions (?) mark in the following questions.
1204, 1218, ? , 1267, 1302, 1344
- What will come in place of the question mark (?) in the following series?
13, 15, 18, 23, 30, ? What will come in place of the question mark (?) in the following series?
325, 292, 262, 229, ?, 166