The product of sum of first 10 even natural numbers and sum of first 10 odd natural numbers is

Sum of first 10 even natural numbers =$n\left(n+1\right)$

$=10\left(10+1\right)$

$=10\times 11=110$

Sum of first 10 odd natural numbers $=n^2$

$={10}^2=100$

$\therefore$ Product $=110\times 100=11000$