11. If a positive integer $\mathrm{x}$ satisfies: the number of digits in $3 x$ is more than the number of digits in $\mathrm{x}$ (for example, the number of digits in 343 is $3,3 \times 343=1029$ has 4 digits), then such an $\mathbf{x}$ is called a “Zhonghuan number”. If all the “Zhonghuan numbers” are arranged in ascending order, the 50th “Zhonghuan number” is ( ).
【Analysis】Single-digit central ring numbers: 4, 9, a total of 6; Two-digit central ring numbers $34 ~ 99$ a total of 66... So the 50th central ring number is the 44th two-digit central ring number, which is $34+(44-1)=77$.