Answer:
The visitor will get both a bumper sticker and free key chain.
Step-by-step explanation:
We are given the following information in the question:
Every visitor gets a bumper ticket in the museum.
Also, every visitor gets a free key chain.
We have to find a visitor that will get both the bumper ticket and the free key chain.
This can be done by finding Lowest common multiple(LCM) of 4 and 10.
Lowest common multiple of 4 and 10 is smallest possible number that is divisible by both 4 and 10.
We can do this with the help of prime factorization.
Hence, the visitor will get both a bumper sticker and free key chain.