Answer:
one gulp is equal to 3
Explanation:
Look at the equations
s=sips, g=gulps,G=glass
5s+4g=G
13s+7g=2G
the first equation is equal to one glass, the second is equal to two
What I did was multiply the first equation by 2, but you have to do it to everything
5s(2)+4g(2)=G(2)
10s+8g=2G
Now this equation is also equal to 2 glasses
then make both equations into a large one
13s+8g=12s+7g
get sips on one side, and gulps on the other.
g=3s
so one gulp is equal to 3 sips
Hope this helped ;)