The sum of first 5 natural numbers is

The correct answer is: 1111(2)

First five natural numbers are 1, 2, 3, 4, and 5
Sum = 1 + 2 + 3 + 4 + 5
= 15
We have to convert the value “15” into binary.
To convert 15 into binary, we will divide it by 2 till we get remainder 1 and quotient 0.
While doing that, we will collect the values of remainder at each step
Then we write the values of remainder from bottom to top.
15 ÷ 2 = 7.           Remainder = 1
7 ÷ 2 = 3             Remaider = 1
3 ÷ 2 = 1              Remainder = 1
1 ÷ 2 = 0            Remainder = 1
Now, we will start from bottom and write all the remainders 1111
So, the binary equivalent of 15 is (1111)₂

For such questions, we should know conversion of decimal numbers to binary numbers and vice versa.