Question

Which of the following numbers is not divisible by \[10\] ?
A. \[10\]
B. \[20\]
C. \[15\]
D. All of the above

Answer 1

Hint: In this question, we need to find the number which is not divisible by \[10\] from the following given numbers. First, we need to know the concept of the divisibility rule of \[10\] that is if the last digit of any number is \[0\] then the whole number is divisible by \[10\] . By using this property, we can check whether the number is divisible by \[10\] or not.

Complete step by step answer:
We need to find the number which is not divisible by \[10\] from the following given numbers.
Divisibility rule for \[10\] :
The divisibility rule for \[10\] is nothing but if any number with its unit digit \[0\], then it is divisible by \[10\] .
First let us check the number \[10\] whether it is divisible by \[10\] or not.
On observing the number \[10\] , the unit digit of the number \[10\] is \[0\] .
Therefore the number \[10\] is divisible by \[10\] .
Next we can check for the number \[20\] .
Now on observing the number \[20\] , the unit digit of the number \[20\] is \[0\] .
Therefore the number \[20\] is divisible by \[10\] .
Then we can check the number \[15\] .
On observing the number \[15\] , the unit digit of the number \[15\] is not \[0\] .
Thus the number \[15\] is not divisible by \[10\] .
And also the last option given is all of the above, so we can just ignore that option.
Hence we get the number \[15\] is not divisible by \[10\] .

Therefore, option (C) is correct. The number \[15\] is not divisible by \[10\].

Note:
In order to solve these types of questions , we must always keep in mind the divisibility rule of the numbers to find out the results easily. The division rule is nothing but which helps us to check whether the given number is divisible by another number without using the actual method of division. We also need to know that if the number is completely divisible by another number then the quotient will be a whole number and the remainder will be zero.