Multiply the amount per week by the number of weeks (x) and add that to the starting amount they had. Set those to equal each other and solve for x:
222 + 10x = 148 + 12x
Subtract 10x from both sides:
222 = 148 + 2x
Subtract 148 from both sides
74 = 2x
Divide both sides by 2
X = 37
Answer: 37 weeks