Number Classification :
In
this case, we need to choose the odd number from the given alternatives. The
numbers may belong to a particular set, i.e. they may be odd, even, prime,
rational, squares, cubes, and they may also be coded into binary digits (involving
0's and 1 's) etc. and only one of the choices will not follow the rule which
others do and that is our answer. A few illustrations are given below.
Example 1.
Find the odd one among the following.
1. .
(a) 17
(b)27
(c) 37
(d) 47
2. .
(a) 441
(b) 289
(c) 361
(d) 343
3.
(a) 1011
(b) 1101
(c) 1111
(d) 10001
Solution
(a) All the given numbers except 27
are prime numbers whereas 27 is a composite number.
Choice (b)
(b) The given numbers can be written as (21)2,
(17)2, (19)2, (7)3.
All except 343 are the squares whereas 343 is a cube.
Choice (d)
