How many numbers between 100 and 1000 have 4 in the unit place?

How many numbers between 100 and 1000 have the digit 7 exactly once?

Find the sum of all natural numbers between 100 and 1000 which are multiples of 7 .

How many numbers are there from 10 to 300 which when divided by 4 leave the remainder 3?

How many numbers can be formed using the digits 0, 1, 2, 3, 4, 5 without repetition so that resulting numbers are between 100 and 1000?

A metallic element exists as a cubic lattice. Each edge of the unit cell is 2.88 A. The density of the metal is 7.20 g/cm^3 . How many unit cells will be there in 100 g of the metal?

How many numbers can be made with the digits 3, 4, 5, 6, 7, 8 lying between 3000 and 4000 which are divisible by 5 while repetition of any digit is not allowed in any number