Answer:
2.67 hours
Step-by-step explanation:
Diana: 15 cookies per hour
Jamie: 7.5 cookies per hour
15 + 7.5 = 22.5
22.5 cookies per hour
[tex]\frac{60}{22.5} =\frac{y}{1}[/tex]
22.5 · y = 60 · 1
22.5y = 60
22.5y ÷ 22.5 = 60 ÷ 22.5
[tex]y=2\frac{2}{3}[/tex]
[tex]2\frac{2}{3}[/tex] rounded to the nearest hundredth is 2.67
