Identify the number which does NOT satisfy: Sum of digits is a factor of the number .

The correct option is 39.

Step-by-Step Explanation:

We are asked to identify the number among the given options for which the sum of its digits is NOT a factor of the number itself.

Let us test each option one by one:

1. Option 24:

Sum of digits = $2+4=6$

Now check if 6 is a factor of 24:

$24÷6=4$ (Since 24 is divisible by 6, 6 is a factor of 24.)

2. Option 36:

Sum of digits = $3+6=9$

Now check if 9 is a factor of 36:

$36÷9=4$ (Since 36 is divisible by 9, 9 is a factor of 36.)

3. Option 42:

Sum of digits = $4+2=6$

Now check if 6 is a factor of 42:

$42÷6=7$ (Since 42 is divisible by 6, 6 is a factor of 42.)

4. Option 39:

Sum of digits = $3+9=12$

Now check if 12 is a factor of 39:

$39÷12=3.25$ (39 is not evenly divisible by 12, so 12 is NOT a factor of 39.)

Therefore, 39 is the number that does NOT satisfy the given condition.