James buys 3 CDs.  Two of them are 1.5 hours each.  The last one is twice that long.  What is the combined length of the CDs?
The long CD is 1.5*2=
<gadget id="calculator">1.5*2</gadget>
<output>3</output>
3 hours.
The two shorter CDs have a combined length of 1.5*2=
<gadget id="calculator">1.5*2</gadget>
<output>3</output>
3 hours.
So in total the CDs had a length of 3+3= 
<gadget id="calculator">3+3</gadget>
<output>6</output>
6 hours.

<result>6</result>