SOLUTION:
Step 1:
In this question, we are meant to solve the following:
45%of what is 81?
Step 2:
Let the unknown number be x, such that:
[tex]\begin{gathered} 45\text{ \% of x = 81} \\ \frac{45}{100}\text{ of x = 81} \\ \\ \frac{45x}{100}=81 \\ \end{gathered}[/tex]Cross-multiply, we have that:
[tex]\begin{gathered} 45x\text{ = 8100} \\ \text{Divide both sides by 45, we have that:} \\ \text{x =}\frac{8100}{45} \\ x\text{ = 180} \end{gathered}[/tex]CONCLUSION:
The final answer is:
[tex]x\text{ = 180}[/tex]