10. As you all know, Nick has been dreaming to be like Spiderman. Spiderman can

Question

10. As you all know, Nick has been dreaming to be like Spiderman. Spiderman can climb up the outside of a building; if he is at a particular floor, then, in one step, Spiderman can move up several floors. Since having finished marking assignment 2, Nick has been working hard to improve his Spiderman-skills: In one step, Nick can move up cither two floors or three floors. (Nick lost his ability to move up one floor in one step.) Let n > 2 be an integer and consider a building with n floors, numbered 1.2, n. (The first floor has number 1; this is not the ground floor.) Nick is standing in front of this building, at the ground level. Let Nn be the number of different ways, in which Nick can climb to the n-th floor. Which of the following is true for any n 257

Explanation / Answer

Since Nick can move up either 2 or 3 floors, to get to floor n, he must've been on either floor n-2 or floor n-3,

So, the number of different ways in which Nick can climb to the nth floor is equal to the number of different ways to the (n-2)th floor plus the number of different ways to the (n-3)th floor .

Answer: d

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.