At 12pm there are 855 people in the zoo. By 5pm ⁴/₅ of the children have left and ³/₄ of the adults have left. There are now 36 more children than adults in the zoo. How many adults were in the zoo at 12pm?

  300

Step-by-step explanation:

Let x represent the number of adults in the zoo at 12 pm. Then the number of children at that time is 855 -x.

The number of remaining children is 1/5 of the number at 12 pm, so is ...

  (855 -x)/5

The number of remaining adults is 1/4 of the number at 12 pm, so is ...

  x/4

There are 36 more remaining children, so we have ...

  (855 -x)/5 -x/4 = 36

  171 -9x/20 = 36 . . . . . collect terms

  135 = 9x/20 . . . . . . . . add (9/20)x-36

  (20/9)(135) = x = 300 . . . . . multiply by 20/9

There were 300 adults in the zoo at 12 pm.

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true