Admission to a show is 30 pesos for each child and 70 pesos for each adult. a group of 12 people pays 640. how many children are in this group

1
by mariepearl18

• Brainly User
2016-01-24T02:33:42+08:00

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Total adult and children = 12 people

x + y = 12
y = 12 - x

Number of children   ⇒       x
Number of adults      ⇒      12 - x

Admission Fee paid by each group:
Children:  30 (x)      ⇒    30x
Adults: 70 (12-x)     ⇒    840 - 70x
Total Admission fee paid = 640

Equation:  Solve x (number of children)
30x + 840 - 70x = 640
-70x + 30x = 640 - 840
-40x = -200
-40x/-40 = -200/-40
x = 5

ANSWER:  The number of children is 5.

Substitute 5 for for number of adults:
Adults: 12 - x = 12 - 5  ⇒  7 adults

Check:
5 + 7 = 12
12 = 12   (True)