Need Help with my math

Question

Tom sells 50 tickets. Some are adult tickets and some are child tickets. Each adult's ticket cost $7 and each child's ticket cost $3. How many of each was sold if he collected $242

Answer 1

You need to create two equations with two variable. 

X - number of adult tickets

Y - number of child tickets

X+Y = 50 - First equation

7X - amount paid for all adult tickets

3Y - amount paid for all child tickets

 

7X + 3Y = 242 - Second equation

You apply substitution : Y= 50- X and put into second equation

7X + 3(50-X) = 242

7X +150 - 3X = 242

4X = 92; X = 23 ; Y = 50-23 = 27;