08:27 - 
Basic Mathematics
No comments
Basic Mathematics
No comments
How many 3 digit numbers can be formed by using the digits 2, 3, 5, 6, 7, 9 repetitions not being allowed i) How many of these are less than 400 ? ii) How many of these are even ? iii) How many of these are multiples of 5 ?
There are 6 digit and we require 3
digit number.
This means we have to fill up 3 places
( units, tenths, and hundredths ) by using
6 digits. Units place can be filled up in 6 ways as we can put any one
of the six digit. After this 5 digits are left behind and 10th place
can be filled up in 5 ways and similarly 100th place can be filled
up in 4 ways.
100
10 1
4 5 6
Therefore the number of ways of
filling up the 3 places = 6 x 5 x 4 = 120
We can just write that no. of ways of
filling up 3 places using 6 digits is
