A cobra, which has 70 spots, has twice as many spots as a mamba. If there are 40 cobras and 60 mambas in a snake park, what is half the number of spots they all have combined?
A cobra, which has 70 spots, has twice as many spots as a mamba, meaning a mamba has 70/2= 
<gadget id="calculator">70/2</gadget>
<output>35</output>
35 spots.
If there are 40 cobras in a snake park, they all have a total of 70*40 = 
<gadget id="calculator">40*70</gadget>
<output>2_800</output>
2800 spots.
60 mambas in a snake park, each having 35 spots, have 60*35 = 
<gadget id="calculator">60*35</gadget>
<output>2_100</output>
2100 spots total.
Together, all the snakes in the park have 2100+2800=
<gadget id="calculator">2100+2800</gadget>
<output>4_900</output>
4900 spots.
Half the number of spots they all have combined is 1/2*4900=
<gadget id="calculator">1/2*4900</gadget>
<output>2_450</output>
2450.

<result>2_450</result>