Let S= 2,3,4,5,6,7,9 . How many different 3-digit numbers (with all digits different) from S can be made which are less than 500 ?

Step-by-step solution

n(s)=7 For 3 digit numbers less than 500 (repetion not allowed) Numbers of digits choice for hundred place (2,3,4)=3 Numbers of digits choice for tens place =6 Numbers of digits choice for once place =5 Total number of 3 digit numbers less than 500 =3 6 5=90