word problem

Question

the jurassic zoo charges $5 for each adult admission and $3 for each child. the total bill for 135 people from a school trip was $471. how many adults and how many children went to the zoo?

Answer 1

Let A = number of adult admissions

Let C = number of child admissions 

 

135 people total  ==>  A + C = 135  ==>  C = 135 - A

 

Total cost 471  ==>  5*A + 3*C = 471 

 

Substitute the value for C from the 1st equation in to the 2nd equation 

 

5*A + 3*(135 - A) = 471

5*A + 405 - 3*A = 471

2*A = 66

A = 33

 

So C = 135 - 33 = 102 

 

So 33 adults and 102 children went to the zoo 

 

Check:  33*5 + 102*3 = 165 + 306 = $471