"Three and seventy five hundredths" is the same thing as saying:

3 + 75/100

We need to convert this into improper fraction form. To do this, we need to convert the 3 into a fraction that has a denominator of 100.

(3 * 100)/(1 * 100) = 300/100

Now we have:

300/100 + 75/100

From this point, ignore the denominators and only focus on the numerators. Then place the sum all over 100.

(300 + 75)/100 = 375/100

Both numbers, 375 and 100, have a common factor of 25. Divide both numbers by 25.

(375/25)/(100/25) = **15/4.**