To convert a fraction to a percentage, we need to multiply the fraction by 100. So, to find the percentage of 42/45, we can use the following formula:

Percentage = (Fraction x 100)

Substituting the values, we get:

Percentage = (42/45 x 100)

Simplifying the fraction, we get:

Percentage = (0.9333 x 100)

Percentage = 93.33%

Therefore, 42/45 as a percentage is 93.33%. This means that if we divide something into 45 equal parts, 42 of those parts would be equivalent to 93.33% of the whole.