Mon to Fri, she saved $0.40 a day. That make $2 for weekdays in a week.
On weekends, she saved $3 a day . That makes it $6 on weekends.
So in a week starting from Monday to Sunday, she saved $8 a week.
No of weeks = 50/8 =6 weeks with a remainder of $2.
Days needed to save the remainder $2 = 2/0.4 = 5days
Total days needed to save $50 = 6 weeks + 5 days
= 42 days + 5 days = 47days##