Since the middle ticket equals to 10, there should be two numbers smaller than 10 and two numbers greater than 10.
The number of ways to draw 2 numbers from 9 (numbers smaller than 10) is "\\binom{9}{2}", the number of ways to draw 2 numbers from 20 (numbers greater than 10) is "\\binom{20}{2}".
The number of ways to draw 5 numbers from 30 numbers is "\\binom{30}{5}".
Probability that middle tickets equal to 10 is "\\frac{}{}" "\\frac{\\binom{9}{2}\\cdot\\binom{20}{2}}{\\binom{30}{5}}="
"\\frac{1\\cdot2\\cdot3\\cdot4\\cdot5\\cdot9\\cdot8\\cdot20\\cdot19}{30\\cdot29\\cdot28\\cdot27\\cdot26\\cdot2\\cdot2}=\\frac{380}{7917}\\approx0.048."
Answer: 0.048.
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