Answer:
Total number of puppies in the litter = 11
Step-by-step explanation:
Let the number of yellow puppies in the litter = y
And the number of black puppies in the litter = b
If there was one less black puppy, ratio of yellow to black puppies =
2(b - 1) = 3y
3y - 2b = -2 -----(1)
If there was one more black puppy, ratio of yellow puppies to black puppies =
2y = b + 1
2y - b = 1 -------(2)
Equation (1) - 2× equation (2)
(3y - 2b) - 2(2y - b) = -2 - 2
3y - 4y - 2b + 2b = -4
y = 4
From equation (1),
3×4 - 2b = -2
12 - 2b = -2
-2b = -14
b = 7
Total number of puppies in the litter = 7 + 4 = 11