Candy has 15 light blue spools of thread, 45 dark blue spools of thread, 40 light green spools of thread, and 50 dark green spools of thread. What percent of her spools are blue?
First find the number of blue spools: 15 spools + 45 spools = 
<gadget id="calculator">15+45</gadget>
<output>60</output>
60 spools.
Then find the total number of spools: 40 spools + 50 spools + 60 spools = 
<gadget id="calculator">40+50+60</gadget>
<output>150</output>
150 spools.
Then divide the number of blue spools by the total number of spools and multiply by 100% to express the answer as a percentage: 60 spools / 150 spools * 100% = 40%

<result>40</result>