Answer:
Sarah will have $200 after 3 weeks
Step-by-step explanation:
amount saved at the start = $20
amount saved per week = $10
number of weeks = 3
∴ Total savings from allowance after 3 weeks = 10 × 3 = $30
Amount received in birthday money = $150
∴ Total amount saved after 3 weeks = amount saved at the start + Total savings from allowance after 3 weeks + Amount received in birthday money
Total amount saved after 3 weeks = 20 + 30 + 150 = $200
Therefore Sarah will have $200 after 3 weeks