Answer:
• Shanna had $10 in her piggy bank and earned $5 each week in allowance.
Explanation:
Week 0 dollars = 10
This means Shanna had $10 her piggy bank before the week started
Week 2 dollars = 20
Her account has increased from 10 to 20 dollars in two weeks. This means she is earning
Amount earned per week = change in earnings / change in week
= 20 dollars - 10 dollars / Week 2 - week 1
= 10 dollars / 2 weeks
= 5 dollars per week
Amount earned per week = $5
Therefore,
• Shanna had $10 in her piggy bank and earned $5 each week in allowance