Answer:
Total surface area of the pyramid = 
Step-by-step explanation:
To find the surface area of the triangular- based pyramid, we will use the formula:
Surface area = Area of base + Area of the three faces
Area of base of the pyramid = Area of equilateral triangle = 

Area of the slant faces of the pyramid is 

Since there are 3 slant surfaces the total surface area of the pyramid =
Answer: CURRENT AGES: C = 35, D = 5 AGES IN 5 YEARS TIME: C = 40, D = 10
Step-by-step explanation:
We need to use algebra here.
Let C = Coffee's age
Let D = Daughter's age
C = 7 x D
C + 5 = 4 x (D + 5)
C + 5 = 20 + 4D
C = 15 + 4D
7D = 15 + 4D
D = 5
C = 7 x 5
C = 35
Answer:
After 10 years the cost will be $ 97.52.
Step-by-step explanation:
This problem requires us to calculate the cost of graphing after 10 years if inflation rate is two percent. This can easily be calculated by compounding present value of current cost at the rate of 2%. Detail calculation is given below.
FV= 80 (1+2%)^10
FV = $ 97.52