I would suggest them to repeat the experiment while including sets from answers to "choose heads or tails" AND "choose tails or heads", ditto for numbers or rephrase the question to not include a "choice" (choose from 0 to 9 (btw, they're asking to choose from 0 to 10 inclusive, which is inherently wrong as the even subset is bigger in this case)), but rather "choose a random integer".
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I would suggest them to repeat the experiment while including sets from answers to "choose heads or tails" AND "choose tails or heads", ditto for numbers or rephrase the question to not include a "choice" (choose from 0 to 9 (btw, they're asking to choose from 0 to 10 inclusive, which is inherently wrong as the even subset is bigger in this case)), but rather "choose a random integer".