3/5
step-by-step explanation:
double number line is not a standard concept, so it must have been defined in your textbook. assume top line is numerator.
5/20 so 25%
let pq = qr = rs = x, and xz = y and zu = z.
if the horizontal lines are parallel, then corresponding segments are in proportion:
substitute:
therefore 3 = y = z.
xu = y + z → xu = 3 + 3 = 6