In order to find an average, you have to add all the numbers and divide by the number of things you added.
120.37 + 108.45 + 114.86 = 343.68
343.68/3 = 114.56
She spent an average of $114.56 each month on groceries.
It depends on the question, but if the questions is sort of like "Person A and Person B shared 40 sweets in the ratio 3:5, how many sweets did Person A get" then you add 3 and 5 to get 8, and then you do 40 ÷ 8 to get 5 which is 1 in terms of the ratio. Then, you would multiply 5 by 3 to get 15 sweets. If it's a different type of question then let me know so I can help out :)
Answer:
920 square feet
Step-by-step explanation:
Top: 20 * 17 = 340
Side triangles: 8 * 15 / 2 = 60
2 side triangles: 60 * 2 = 120
Back rectangle: 8 * 20 = 160
Bottom rectangle: 15 * 20 = 300
All of them: 340 + 120 + 160 + 300 = 920