The question is in the photo.

Step-by-step explanation:

The formula for determining the nth term of an arithmetic sequence is expressed as

f(n) = a + d(n - 1)

Where

a represents the first term of the sequence.

d represents the common difference.

n represents the number of terms in the sequence.

From the information given,

a = 13

d = 24 - 13 = 11

14) Therefore, the explicit formula for the arithmetic sequence is

f(n) = 13 + 11(n - 1)

15) when n = 40,

f(n) = 13 + 11(40 - 1)

f(n) = 13 + 429

f(n) = 442

16) if f(n) = 299,

299 = 13 + 11(n - 1)

11(n - 1) = 299 - 13

11(n - 1) = 286

Dividing through by 11, it becomes

n - 1 = 286/11 = 26

n = 26 + 1

n = 27

the correct answer option is d. la = πrs.

step-by-step explanation:

we know that for a right cone, the lateral surface area is given by:

lateral area of right cone =

here the value under the square root is equal to slant height so replacing this value by in the formula to get:

lateral area of right cone =

therefore, the correct answer option is d.