Answer:
300
Step-by-step explanation:
[tex]\frac{225}{x} = \frac{75}{100}[/tex]
Since 225 is 75% of a whole, write the proportion such that 225 corresponds to 75% and x, the number we're searching for, corresponds with 100%
Cross multiply to solve and divide by 75 to isolate x:
225 x 100 = 75x
22500 = 75x
300 = x