This how my teacher helped me understand a problem like this. You are looking for a percentage to plug in. This percentage will be represented by x. To make it easier you can think of the equation as a sentence and then plug in the signs:
180 IS what percent OF 5400 Which would translate mathematically to: 180 = x * (Multiply) 5400
Then you solve for x! x = 180/5400 x = 0.0333333.... which would equal roughly 3% (move decimal 2 places right).
Then plug it into your new equation: 3% OF 8100 IS what? y will represent our final answer.
(You should convert the percent back to decimal form though. or just keep it there, it was easier for me to understand when i converted it)
