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3 years ago

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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?

1 answer:

True [87]3 years ago

5 0

Answer:

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.

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