CAT 2019 Shift 2 Paper

Let a be the average of 20 numbers whose average does not exceed $5.$
Let b be the average of rest of the 10 numbers. Clearly, b>5 i.e. the average of these numbers exceeds 5
Therefore,
$30\times 5=20\mathit{a}+10\mathit{b}$
$\Rightarrow 2\mathit{a}+\mathit{b}=15$
$\Rightarrow \mathit{b}=15-2\mathit{a}$
Going by the options, we can say that when $\mathit{a}=4.5,\mathit{b}=6$ which satisfies all the conditions.