Excercise 8H
In how many ways can 5 boys and 3 girls be seated in a row so that each girl is between 2 boys?
How many 5-digit numbers can be formed by using the digits 0, 1 and 2?
In how many ways can 4 letters be posted in 5 letter boxes?
Answer : Given: We have 4 letters and 5 letter boxes To Find: Number of ways of posting letters. One letter can be posted in any of 5 letter boxes. We have to assume that all the letters are...
How many words can be formed by the letters of the word ‘SUNDAY’?
How many permutations of the letters of the word ‘APPLE’ are there?
How many different words can be formed by using all the letters of the word ‘ALLAHABAD’?
In how many ways can the letters of the word ‘PERMUTATIONS’ be arranged if each word starts with P and ends with S?
In how many ways can the letters of the word ‘CHEESE’ be arranged?
How many numbers divisible by 5 and lying between 4000 and 5000 can be formed from the digits 4, 5, 6, 7, 8 if repetition of digits is allowed?
How many 3-digit numbers above 600 can be formed by using the digits 2, 3, 4, 5, 6, if repetition of digits is allowed?
. How many 3-digit numbers are there with no digit repeated?
find the value of x.
If (n + 1)! = 12 × [(n – 1)!], find the value of n.
Answer : To Find: Value of n Given: (n+1)! = 12× [(n-1)!] Formula Used: n! = (n) × (n-1) × (n-2) × (n-3)............. 3 × 2 × 1 Now, (n+1)! = 12× [(n-1)!] ⇒ (n+1) × (n) × [(n-1)!] = 12 × [(n-1)!] ⇒...
Find the greatest possible length which can be used to measure exactly the lengths 7m, 3m 85cm and 12m 95cm.
Answer: Given lengths are 7m (700cm), 3m 85cm (385cm) and 12m 95m (1295cm). The required length = HCF (700, 385, 1295) Using prime factorization, 700 = 2 × 2 × 5 × 5 × 7 = 22 × 52 × 7 385 = 5 × 7 ×...
Three pieces of timber 42m, 49m and 63m long have to be divided into planks of the same length. What is the greatest possible length of each plank? How many planks are formed?
Answer: The lengths of three pieces of timber are 42m, 49m and 63m Divide the timber into equal length of planks. ∴ Greatest possible length of each plank = HCF (42, 49, 63) Using prime...