A boat can cover 66 km upstream and 165 km downstream in 13 hours. Speed of the stream is how much less than the speed of the boat in still water if the boat can cover 55 km upstream and 110 km downstream in 9 hours?
ATQ, Let the upstream speed and downstream speed of the boat be x km/h and y km/h, respectively. So according to question: 66/x + 165/y = 13 ………………. (i) Also, 55/x + 110/y = 9 ……….. (ii) Solving (i) and (ii), we get x = 11 and y = 22 So, the upstream speed and downstream speed of the boat are 11 km/h and 22 km/h, respectively. Speed of the boat in still water = (11 + 22)/2 = 16.5 km/h Speed of the stream = (22 – 11)/2 = 5.5 km/h So, the desired difference = 16.5 – 5.5 = 11 km/h
A bag contains cards which are numbered from 2 to 90. A card is drawn at random from the bag. Find the probability that the card number is a perfect squ...
If the letters of the word HORIZON be arranged at random, what is the probability that vowels are not together?
There are 5 Red caps, 3 Green caps and 2 Blue caps in a box. 4 caps are chosen at random. What is the probability of their being 2 Red and 2 Blue caps?
A box contains only three colors of balls- red, green and blue. What is the minimum number of balls that should be picked from the box to ensure that at...
In a jar, there are (x + 8) red balls, ‘x’ blue balls, and (x + 2) black balls. If the probability of picking two blue balls at random is (1/45), th...
A bag contains 7 (one rupee coins), 4 (two rupee coin) and 5 (ten rupee coin). Find the probability that 3 coins drawn at random are either (two rupee c...
5 coins are tossed together. What is the probability of getting exactly 3 tails?
A box contains only three colors of balls- red, green and blue. What is the minimum number of balls that should be picked from the box to ensure that at...
19 rotten bananas are accidentally mixed with 136 good ones. It is not possible to just look at a banana and tell whether or not it is rotten. One banan...
A bag contains 10 black and 12 white balls. One ball is drawn at random. What is the probability that the ball drawn is white?
