Number of dogs in the shelter in the last week is 35
<u>Step-by-step explanation:</u>
Step 1:
Given in the first week of Jan, there are 49 dogs and 28 cats, find the ratio between them.
Ratio = 49/28 = 7/4
Step 2:
Since the ratio remains constant, use it to find the number of dogs in the shelter when cats = 20 in the last week of Jan.
Number of dogs/20 = 7/4
∴ Number of dogs = 20 × 7/4 = 35