Question

Jamie is buying 5 concert tickets, and he wants his total coast to be no more than $4 above or below $80. Write an inequality that models the cost x, in dollars, of a ticket?

Answer 1

Number of concert tickets Jamie wants to buy = 5

Constraint on total cost is that it should be not beyond $4 above or below $80

Cost of a ticket = x

⇒ 80-4 < x*5 < 80+4

⇒ 76 < 5x < 84

⇒ $\frac{76}{5}$ < x < $\frac{84}{5}$

⇒ 15.2 < x < 16.8

Hence, the inequality that models cost x is: 15.2 < x < 16.8

Answer 2

It is given that the cost is x dollars.

The cost should be no more than $4 above.

Therefore, x ≤ 4

Also, the cost should not be below $80.

Therefore, x ≥ 80

If we combine the inequalities, we get,

80 ≤ x ≤ 4

But, clearly no value satisfies the above inequality.