In a class containing 200 students, \( n \) students prefer both tea and coffee; \( 2n \) students prefer coffee; \( 3n \) students prefer tea; \( 4n \) students prefer neither tea nor coffee. What is the value of \( n \)?
Let \( n \) be a natural number. The HCF of \( n \), and \( (n + 10) \) is 10. If the LCM is \( x \) (a 2-digit number), then how many values of \( x \) are possible?