Here's the answer I got:
A. After 4 weeks, Olivia has $240 and Evelyn has $150. Olivia has more money in their savings. Olivia started with $200, after 4 weeks Olivia had saved 40 dollars because she adds 10 each week. Evelyn starts with $50 and adds 25 dollars each week, 25x4 is 100 so in total she has $150.
B. After 10 weeks they will both have $300 in their savings.