Question 1187293
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Let x be the original number of long rulers
Then 540-x is the original number of short rulers<br>
At the end, he had 1/3 of the original number of long rulers left, so he sold 2/3 of the original number.<br>
At the end, he had 1/6 of the original number of short rulers left, so he sold 5/6 of the original number.<br>
The numbers of long and short rulers he sold were the same:<br>
{{{(2/3)x = (5/6)(540-x)}}}<br>
Solve using basic algebra; I leave that to you.<br>
Perhaps start by multiplying both sides of the equation by 6 to clear fractions:<br>
{{{4x = 5(540-x)}}}
....<br>