The number 3 can be written as 3, 2+1, 1+2 or 1+1+1 in four ways. In how many ways number n can be written as??

A number of four different digits is formed with the help of the digits 1, 2, 3, 4, 5, 6, 7 in all possible ways. Find how many such numbers can be formed ?

Numbers 1,2, and 3 are written on three cards. How many two digit numbers can be formed by placing two cards side by side?

Numbers 1,2, and 3 are written on three cards. How many two digit number4s can be formed by placing two cards side by side?

In 3 fingers , the number of ways four rings can be worn is ……ways

In how many ways a composite number can be written as product of power of primes ?