Question
The number of five–digit telephone numbers having
at least one of their digits repeated isSolution
The number of five–digit telephone numbers which can be formed using the digits of 0, 1, 2,...., 9 is 105. The number of five-digit telephone numbers which have none of their digits repeated is 10P5 = 10 × 9 × 8 × 7 × 6 = 30240 Hence the required number =105 - 30240 = 69760
The LCM of two numbers is 1991 and their HCF is 23. If one of the numbers is 181, the other number is
The H.C.F. of two numbers is 14 and the other two factors of their L.C.M. are 5 and 11. The larger of the two numbers is:
Find the HCF (GCD) of 48 and 72.
If total number of factors of 2,430 is 'x', then find the value of (x - 6)(x + 1).
A man deposits Rs. 25,000 at a simple interest rate of 8% per year. What amount will he receive after 5 years?
Rohit spends an average of Rs. 500 on Sundays and Rs. 350 on the remaining days. Find his average spending in a 30-day month starting with Sunday.
What is the difference between the LCM and HCF of 38, 52?
The HCF and LCM of two natural numbers are 15 and 75, respectively. What is the difference between the two numbers, if one of the numbers is 25?
Find the LCM of 36, 45, 60, 80.
The smallest number which when divided by 22 and 34 leaves remainder 10 and 22 respectively is:
