Answer:
We can use algebra to solve this problem. Let's call the unknown number x.
We are given that 10% of x is 40, so we can write that as:
x * 10% = 40
x * 0.1 = 40
We are also given that 55% of x is 220, so we can write that as:
x * 55% = 220
x * 0.55 = 220
We can now use these two equations to solve for x.
From the first equation, x = 40 / 0.1 = 400
We can substitute that value of x into the second equation to check if it's true.
400 * 0.55 = 220
Now, we have the value of x, we can use it to find 65% of that number.
x * 65% = x * 0.65 = 400 * 0.65 = 260
So, 65% of that number is 260