Question

The cost of tickets of a comedy show of 'Gaijatra' is Rs 700 for an adult and Rs 500 for a child. If a family paid Rs 3,100 for 5 tickets, how many tickets were purchased in each category? ​

Answer 1

Explanation:

We need to create a system of equations here, one for the NUMBER of tickets sold and one for the COST of the tickets. They are very much NOT the same thing.

We have that the total number of tickets is 5, and that that total is made up of adult tickets and child tickets. The equation for the NUMBER of tickets, then, is:

a + c = 5

Now for the money.

If a child ticket costs Rc 500, the expression that represents that that is in fact the cost of the child ticket is 500c;

likewise for the adult ticket. If the adult ticket costs Rc 700, the expression that represents that is 700a.

And we know that a total of Rs 1300 was spent on the tickets. The equation for the COST is

700a + 500c = 1300

Now go back to the first equation and solve it for either a or c, it doesn't matter which. I solved for a:

a = 5 - c and we will sub that into the second equation for a:

700(5 - c) + 500c = 1300 and

3500 - 700c + 500c = 1300 and

-200c = -400 so

c = 2 tickets. That means that there were

a = 3 tickets sold for the adults.