Stella has five times as many books as Tina. If Stella gave 16 books to Tina, they would each have the same number of books. How many books does Stella have? ​

40 books

Step-by-step explanation:

s = Stella's books

t = Tina's books

Given:

s = 5t

s - 16 = t + 16

Plug first equation into second:

5t - 16 = t + 16

4t = 32

t = 8 books

s = 5t = 40 books

((Check: 40 - 16 = 24 = 8 + 16 ✔ ))

look at the picture.

1.

ef : ab = 2 : 3

gf : cb = 2 : 3

gh : cd = 2 : 3

he : da = 2 : 3

2.

∠a ≅ ∠e

∠b ≅ ∠f

∠c ≅ ∠g

∠d ≅ ∠h

3.

use pythagorean theorem:

the length of the abcd trapezoid sides:

|ab| = 3 cm

|bc| = 10 cm

|cd| = 3(3) cm = 9 cm

|da| = 8 cm

the perimeter of abcd = 3 + 10 + 9 + 8 = 30 cm

the ratio of perimeters of the tarapezoids is equal 2 : 3.

substitute:

      cross multiply

      divide both sides by 3