The square root of which of the following integers is between 7 and 8

Lilianna uses 3/4 calories per minute just by sitting. she uses 1 more calorie per minute by walking. lilianna uses a total of 12 1/4 calories walking to the park. lilianna uses the equation, d(.75+1)=12.25 to represent the situation. what does the variable d represent in the equation?

Cody worked 42.5 hours per week in july. this is 12.25 hours more per week than he worked in june. how many hours did cody work per week in june?

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?