Answer:
The first customer that will get four free tickets is 50th customer
Step-by-step explanation:
Find the least common multiple of numbers 10 and 25. First, factorize these numbers:
[tex]10=2\cdot \underline{5}\\ \\25=\underline{5}\cdot 5\\ \\LCM(10,25)=\underline{5}\cdot 2\cdot 5=50[/tex]
When finding LCM, first write the all common multiples (underlined 5) and then multiply them by remaining multiples (2 and 5). You get 50 as LCM(10,25). This means that each 50th customer will get four free tickets.
