Greg has 16 clients. Dolores has 75% as many clients as Greg, then
16 - 100%
x - 75%
Write proportion:

This means that Dolores has 12 clients.
Together Dolores and Greg have 16+12=28 clients.
If Robert has 25% as many clients as Greg and Dolores together, then
28 - 100%
y - 25%
Mathematically,

Therefore, Greg, Dolores and Robert have 16+12+7=35 clients.
Answer: 35 clients.