find the sum of $2.\overline{3}$ and $4.\overline{15}$

Q. $2.\overline{3}-0.\overline{4}=$______.

Q. Find the sum of the first 'n' natural numbers and hence find the sum of first 20 natural numbers.

Q.

Find the sum of the additive inverse of -13, 24, and -10. Also, find the multiplicative inverse of the sum obtained.

Q. Find out the sum of 4,521 and the final sum of the numbers given below.

Q. The sum of two numbers is 7 and the sum of their cubes is 133, find the sum of their squares.