Question
A Boat travel 80 km distance in downstream and 48 km
upstream and the total time taken is 20 hours. The same boat travels 30 km distance in downstream as much time travel 12 km in upstream. Find the speed of boat in still water?Solution
Let the speed of stream be x And speed of Boat be y Total time taken =80/(x+y) + 48/(x - y) = 20 ………………………. (i) And time taken for 30 km in downstream and 12 km in upstream is equal 30/(x + y) = 12/(x - y) 5x – 5y = 2x + 2y 3x = 7y x/y = 7/3 Now x = 7k and y = 3k Put the value of x and y in equation (i), 80/(7k + 3k) + 48/(7k - 3k) = 20 80/10k + 48/4k = 20 8/k + 12/k = 20 20/k = 20 k = 1 Therefore the speed of Boat in still water is 7 × 1 = 7 km/hr
If it is possible to make a meaningful English word from the 2nd, 5th, 6th and 8th letter of the word ‘FR...
3 : 12 :: 6 : ?
If it is possible to make a meaningful four letters English word using 2nd , 4th, 7th and 10th letters of th...
Select the combination of numbers so that the letters arranged accordingly will form a meaningful English word.
A group of alphabets are given with each being assigned a number. These have to be unscrambled into a meaningful word and correct the order of letters m...
If a four-letter meaningful English word is formed by using the 1st letter, the 3rd letter, the 5th letter and the 10th letter (from the left end) of th...
A group of alphabets are given with each being assigned a number. These have to be unscrambled into a meaningful word and correct the order of letters ...
In a certain code language, ‘4922945’ is related to 'DIVIDE' in the same way ‘1412091514’ is related to which of the following words?
...How many such digits are there in the number ‘738429561’ which will remain at the same position when they are arranged in the ascending order from l...
A group of alphabets are given with each being assigned a number. These have to be unscrambled into a meaningful word and correct the order of letters m...