Which of the following cannot be the class equation of a group G of order 10?

abstract-algebra group-theory finite-groups

1+2+3+4 means there are four distinct conjugate classes having order 1,2,3 & 4. Since, |cl(a)|.|N(a)|=|G|, then for class of order 3, 3.|N(a)|=10. But 10 is not multiple of 3.Hence the class equation is not possible.

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