How to add css hover over show effect in 5 minutes

letters, $ and _

Add css in your Post's HTML

<style>
.showme {
    display: none;
}

.showhim:hover +.showme {
    display: block;
}
</style>

Add the following code in post HTML

<button class="showhim">Show Answers</button>
<div class="showme">
letters, $ and _
</div>