Answer:
3/4 are over 10 years old;
1/3 of the rest is between 3 and 5 years old, i.e. 1/4*1/3 =1/12
collies between 6 and 10 years old:
1-3/4-1/12 =(12-9-1)/12 = 2/12 = 1/6
we know that these 1/6 represent 2 dogs
if 1/6 = 2dogs
6/6 all dogs = 2*6 = 12
are there dogs in total at this rescue shelter: 12
Explanation: