Kenny is selling his Pokemon cards to buy a ticket to an amusement park, which costs $100. He has a collection of cards and plans to sell them for $1.5 each. He keeps 1/3 of them and gets to go to the amusement park with $50 in spending cash. How many cards did he start with?
He made $150 selling the cards because 100 + 50 = 
<gadget id="calculator">100+50</gadget>
<output>150</output>
150.
He sold 100 cards because 150 / 1.5 = 
<gadget id="calculator">150/1.5</gadget>
<output>100</output>
100.
The cards he sold were 2/3 of his collection because 1 - (1/3) = 2/3.
He started with 150 cards because 100 / (2/3) = 
<gadget id="calculator">100/(2/3)</gadget>
<output>150</output>
150.

<result>150</result>