All tickets for a concert are at the same price. Amy and Dan pay £63 altogether for some tickets. Amy pays £24.50 for 7 tickets. How many tickets does Dan buy?

Firstly, we translate the information give into Maths equation. Therefore, A+D=£63 (the amount of many the spend on the tickets). Given the amount spent by Amy, we can find the total amount Dan spends: D=£63 - A= £63 -£24.50=£38.50. This amount represents: the number of tickets * the price per ticket. Hence, the number of tickets bought by Dan will be equal to: 38.50 / the price per ticket.To find the price per ticket we use the information given about Amy: 7 * the price per ticket = £24.50. Hence, the price per ticket = £24.50 / 7 = £ 3.5. Substituting this value, in the formula above we get that the number of tickets bought by Dan = £38.50 / £3.5 = 11. We can verify the answer by substituting in the first equation 7 * £3.5 + 11 * £3.5 = (7 + 11) * £3.5 = 18 * £3.5 = £63