Question
Two trains of same length are running in parallel tracks
in the same direction with speed 40 km/hr and 100 km/hr respectively. The latter completely crosses the former in 27 seconds. Find the length of each train (in m).Solution
When two trains cross each other, they cover distance equal to the sum of their lengths with relative speed. Let's take length of each train = x So, total length of both trains = 2x Relative speed = (100 – 40) × (5/18) = 50/3 m/sec. ∴ Total length = Time × Relative speed ⇒ 2x = (27 × 50)/3 ⇒ x = 225 m
A bag contains 6 purple balls, 9 yellow balls and 5 green balls. Three balls are drawn at random. Find the probability that at least two balls are yellow.
There are (m + 4) red roses, (m + 11) white roses and ‘m’ pink roses in a bag. If the probability of picking a pink rose is 5/16, then find the valu...
- A bag holds 20 balls, each labeled with a unique number that follows a sequence of consecutive multiples of 5, beginning with 5. What is the probability of...
If the letters of the word PARAM are arranged at random, what is the probability that all vowels will come together?
In a group of artists, there are 10 dancers and 8 singers. If four artists are to be selected at random, what is the probability that 2 dancers and 2 si...
In a box, there are three different colour cubes: blue, green, and orange. The sum of the number of green and blue cubes in the box equals the number of...
A card is drawn randomly from a collection of total face cards. What is the probability that the drawn card is a Queen?
There are 'x' one-rupee coins, 'x + 5' two-rupee coins, and 'x - 5' five-rupee coins in a purse. Two coins are drawn from the purse without replacement,...
There are (m + 4) red roses, (m + 9) white roses and ‘m’ pink roses in a bag. If the probability of picking a pink rose is 3/10, then find t...
A bowl contains 9 blue balls, 7 white, and 5 black balls. If 2 balls are drawn in one go, then the probability of exactly one ball being blue is:
Relevant for Exams:
