Please help I dont understand

First team collected 20 books, Second team collected 30 books, Third team collected 15

Step-by-step explanation:

Let us find all equation for n (books)

First team : n - 10

Second team : n

Third team : .3(n + n - 10)

Distributive property :

n+n-10 + .3 * (2n-10)= 65

2.6n = 78

n = 30 (Second team)

n - 10 = 20 (First team)

.3(2n-10)=15 (Third team)

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.