Question

The number of 6 digit numbers that can be formed from 0,1,5,6,7 and 8 in which is the first digit is not 0 are
A.120
B.600
C.720
D.800

Answer 1

Answer:

B.600

Step-by-step explanation:

Given numbers are 0,1,5,6,7 and 8

We have to form a six-digit number in which the first digit should not be zero.

Since we have given six different digits and one of them is 0 but we can't use it as the first digit.

So we can fill the first digit place in 5 different ways. Now, we are left with remaining 5 numbers so second digit place can be filled in 5 ways. Since we have filled 2 places now we have 4 digits so the third place can be filled in 4 ways, fourth in 3 ways, fifth in 2 ways and sixth in 1 way.

So, the number of digit that can be formed by using these digit will be,

N = 5 x 5 x 4 x 3 x 2 x 1

   = 600