Mary earns $20 washing cars and $40 walking dogs each month. If she puts half of that money away each month how long would it take her to save $150?
Each month she makes 20+40=$<<20+40=60>>60
Every month she saves 60/2=$<<60/2=30>>30
To save $150 it will take her 150/30=<<150/30=5>>5 months
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