Gillian earns 7.50 and hour babysitting on the weekends last week she babysat for 2.2 hours on saturday and 3.5hours on sunday how much did gillian earn

Gillian earned $42.75 total. On Saturday (2.2 hours * 7.50 per hour) she earned $16.50. On Sunday (3.5 hours * 7.50 per hour) she earned $26.25. $26.25 + $16.50 = $42.75.

I'm guessing you mean the total that Gillian earned.

First, add the amount of hours she babysat in total: 
2.2 + 3.5 = 5.7
Now multiply the answer by the amount she earns per hour: 
7.50 x 5.7 = 42.75
Your final answer is: Gillian earned $42.75.