A farm has 10 2-legged animals and 15 4-legged animals. If all animals are healthy, how many pairs of animal legs in total are on the farm?
2-legged animals have 2 legs. Therefore 10 2-legged animals will have 10*2=
<gadget id="calculator">10*2</gadget>
<output>20</output>
20 legs
4-legged animals have 4 legs. Therefore 15 4-legged animals will have 15*4=
<gadget id="calculator">15*4</gadget>
<output>60</output>
60 legs.
In total there are 20+60= 
<gadget id="calculator">20+60</gadget>
<output>80</output>
80 legs.
A pair of legs equals 2 legs. If there are 80 legs on the farm, there will be 80/2= 
<gadget id="calculator">80/2</gadget>
<output>40</output>
40 pairs of legs.

<result>40</result>