Question
A motor boat covers a certain distance downstream in a
river in 3 hours. It covers the same distance upstream in 3 hours and 30 minutes. If the speed of water is 1.25 km/h, then the speed of the boat in still water is:Solution
Let the speed of boat in still water be x km/hr and the distance be y km. Rate downstream = (x + 1.25) km/hr Rate upstream = (x – 1.25) km/hr According to the question, y/(x + 1.25) = 3 --- (i) y/(x – 1.25) = 7/2 --- (ii) On dividing equation (i) by (ii), (x – 1.25)/(x + 1.25) = 3/(7/2) = 6/7 7x – 8.75 = 6x + 7.5 x = 8.75 + 7.5 = 16.25 kmph
3. 8, 15, 24, 34, 48, 63
Select the wrong term in the series.
44, 47, 41, 50, 38, 53, 40
Select the wrong term in the series.
10, 19, 23, 52, 61, 133, 149
Find the wrong number in the following number series:
2500, 1000, 400, 160, 60
A series is given with one wrong term. Select the wrong number from the given series.
17, 29, 43, 59, 77, 97, 112
8, 20, 48, 108, 232, 482
In this question, one term in the number series is wrong. Find out the wrong term.
130, 135, 143, 154, 168, 183, 205
Find the wrong number.
17, 25, 37, 47, 65, 81
Arrange the following words in a logical and meaningful order.
1. Monkey
2. Elephant
3. Rat
4. Fly
5. Lion
Select the number from among the given options that is wrong in the following series.
22, 30, 46, 78, 146, 270
