Becky pays $10.4 per week
Cost per week: 7.25
TIp percentage: 40%
First, multiply the cost of the paper ($7.25) by the tip percentage in decimal form ( divided by 100) to obtain the tip amount:
7.25 (40/100) = 7.25 (0.4) = $2.9
Now, add the cost and the tip amount:
7.25+2.9 = $10.4