How many 2 digit number are there using1,4,5,7,8,9

Step-by-step explanation:

If digits can be repeated:

On the first and second place we have 6 digits to choose from.

Therefore we have 6 · 6 = 36 two-digit numbers.

If the digit can not be repeated:

On the first place we have 6 digits to choose from and on the second place we have 5 digits to choose from.

Therefore we have 6 · 5 = 30 two-digit numbers.

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐

1/8 3/16 3/4

step-by-step explanation:

you put them as all the same denominator and multiply