Help me pls this is due tomorrow at 8:00 am

Twenty-five percent of the customers entering a grocery store between 5 p.m. and 7 p.m. use an express checkout. consider five randomly selected customers, and let x denote the number among the five who use the express checkout.

What is the value of the expression below? (81^2)^1/8

Explain how you can find the missing fraction in 3 4/5 / (blank) 2 5/7. then find the missing fraction.