a pet store has a total of 16 snakes, guinea pigs, and miniature poodles. The number of guinea pigs is 1 more than the number of miniature poodles, and 2 fewer than the number of snakes. How many snakes are there in the pet store.
16 = snakes + guinea pigs + miniature poodles
s=snakes, g=guinea pigs, m=miniature poodles
16 = s + g + m
g = 1 + m
s = 2 + g
So:
16 = (2 + g) + (1 + m) + m
16 = 2 + (1 + m) + (1 + m) + m
Combine like terms:
16 = 4 + 3m
12 = 3m
4 = m
Since g = 1 + m:
g = 5
Since s = 2 + g:
s = 7
so the shop has 7 snakes