Brad plans to bike 15 3/4 miles. he has gone 2/3 of the entire distance. how far has he gone?

It'll be easier doing this as improper fractions.
15 3/4= 63/4

To find a fraction of another number, we have to multiply them

(2/3)(63/4)
126/12

Then, we want to make this a mixed number again so it's easier to tell what 126/12 actually means.

126/12 = 10 6/12 = 10 1/2

In conclusion, Brad has gone 10 1/2 miles