How do you do b = 3/8 x 8/11

plse help i really dont understand this.

u/v * w/x = (uw)/(vx), and (fg)/(fh) = g/h where f <> 0 so
b = 3/8 x 8/11 = (3*8)/(8*11) = 3/11

b = 3/8 x 8/11
b = 3/11.