500 tickets were sold for a concert tickets for adults and children were sold at $4.50 and $3.00  respectively if the total receipts for the concerts was $1987.50 how many tickets for adults were sold?

A.

325

B.

235

C.

175

D.

400

Correct answer is A

A for Adults

C for children 

a + c = 500

c = 500 - a

4.5a + 3c = 1987.50

where c = 500 - a

4.5a + 3(500 - a) = 1987.50

4.5a - 3a = 1987.50 - 1500

1.5a = 487.5

a = 487.5 / 1.5

a = 325 tickets

c = 500 - a

c = 500 - 325

c = 175 tickets

 

Check:

from 4.5a + 3c

4.5 (325) = 1,462.5

+

3(175) = 525