Amazon Interview Questions

heap queue level order traversal 3)An anti aircraft gun can fire four shots at a time. If the probabilities of th e first, second, third and the last shot hitting the enemy aircraft are 0.7, 0.6 , 0.5 and 0.4, what is the probability that four shots aimed at an enemy aircraf t will bring the aircraft down? 1. 0.084 2. 0.916 2. 0.036 4. 0.964 Correct Answer - (4) Solution:

The enemy aircraft will be brought down even if one of the four shots hits the a ircraft. The opposite of this situation is that none of the four shots hit the aircraft. The probability that none of the four shots hit the aircraft is given by (1-0.7) (1-0.6)(1-0.5)(1-0.4) = 0.3*0.4*0.5*0.6 = 0.036 So, the probability that at least one of the four hits the aircraft = 1 â 0.036 = 0. 964.

1) What is the return value of f(p, p) if the value of p is initialized to 5 bef ore the call? Note that the first parameter is passed by reference, whereas the second parameter is passed by value. int f(int &x, int c) { c = c - 1; if (c == 0) return 1; x = x + 1; return f(x, c) * x; } (A) 3024 (B) 6561 (C) 55440 (D) 161051 Answer (B) Since c is passed by value and x is passed by reference, all functions will have  same copy of x, but different copies of c. f(5, 5) = f(x, 4)*x = f(x, 3)*x*x = f(x, 2)*x*x*x = f(x, 1)*x*x*x*x = 1*x*x*x*x = x^4 Since x is incremented in every function call, it becomes 9 after f(x, 2) call. So the value of expression x^4 becomes 9^4 which is 6561.