(1, 4), (2, 2) , (5, 8) use quadratic regression to find a function that fits the following points.

Cost of 7 gallons=$24.50

Cost of 1 gallon=24.50/7=3.5

Cost of 15 gallons=15*3.5=52.5

Cost of 15 gallons will be $52.5

The answer is in the image 

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The answer is in the image 

Let the father's age be x and son's be y

10 years before-

Father age=x-10

sons age=y-10

Given,

x-10=10(y-10)

x-10=10y-100

Given present age of father=40

therefore,

x=40

40-10=10y-100

10y-100=30

10y=130

y=130/10

y=13

Therefore present age of son=13years

The answer is in the image 

There are 6 outcomes 1,2,3,4,5,6

Total outcomes = 6

Outcomes when rolling a number is 4 or less = 1,2,3,4

Total outcome when rolling a number is 4 or less=4

Probability = required outcome/total outcome

                 =4/6

                 =2/3

Therefore probability = 2/3

Weight of adult elephant = 24,000 pounds

Weight of baby elephant = 260 pounds

Difference between weight = 24,000 - 260 = 23,740

Adult elephant weights 23,740 pounds more 

(​1 or 7) ; number of possible outcome = 2

(a, e,​ i, o, or​ u) ; number of possible outcome = 5

So,

Number of possible outcomes = 2 x 5

Number of possible outcome =10

Total fabric purchased = 1 1/4 = 5/4

Fabric used = 3/4

Fabric left = 5/4 - 3/4

                 = 2/4

                 =1/2 yard