Speed of train = 90 × 5/18 = 25 m/s Length of train = 25 × 8 = 200 metres Desired time = (300 + 200)/(1.25 × 25) = 16 seconds
In a group of 5 boys and 4 girls, 5 students have to be selected. In how many ways it can be done so that only 2 boys are included.
In how ways can the selection be made so that a particular member is always included?
...How many different nine digit numbers can be formed from the number 66 55 99 222 by rearranging its digits so that the odd digits occupy even positions...
A three-letter word is to be formed using the English alphabet where the first letter is a vowel, the second letter is a vowel different from the first,...
How many no. of 4 digits can be formed with the digits 4, 8, 7 & 3 no digit being repeated.
...In how many different ways can the letters of the word ‘FLOWER’ be arranged in such a way that the vowels occupy only the odd positions?
Geography books are always together.
A Consignment of 12 mobile phones contains 4 defectives. The mobile phones are selected at random one by one and examined. The ones examined are not pu...
In how many ways can three girls and three boys be seated in a straight line such that three girls never sit together?
In how ways can the selection be made so that a particular member is always excluded?
