ANSWER – http://puzzlefry.com/puzzles/crossing-the-bridge-puzzle-bridge-and-torch-problem-2/

Answer – http://puzzlefry.com/puzzles/25-horses-5-tracks-puzzle/

“Silence“

Silence is so delicate that even mentioning Breaks Silence by creating noise.

ITERATIVE SOLUTION-

 /*
 * File:   main.cpp
 * Author: akash
 *
 * Created on 12 August, 2015, 4:57 PM
 */
#include <stdio.h>
 #include <stdlib.h>
struct node
 {
 int data;
 struct node* next;
 };
 //void push(struct **node top_head,int dataToEnter);
 //int getCount(struct *node top_head);
void push(struct node** top_head,int dataToEnter)
 {
 struct node* add_node = (struct node*) malloc(sizeof(struct node));
add_node->data = dataToEnter;
 add_node->next = (*top_head);
 (*top_head) = add_node;
 }
int getCount(struct node* top_head){
 if (top_head == NULL)
 return 0;
// count is 1 + count of remaining list
 return 1 + getCount(top_head->next);
 }
int main(){
 struct node* head = NULL;
push(&head, 10);
 push(&head, 20);
 push(&head, 30);
 push(&head, 40);
 push(&head, 20);
 push(&head, 30);
printf("Nodes Count is %d", getCount(head));
 return 0;
 }
 

The letter “E”.

considering word “week”, it has two similar letters that is “E”
and for the word year, has one “E”.

1   2    3

SUM            = 1+2+3=6
PRODUCT = 1*2*3 =6

Four Coins

Three coins placed flat on the table in a triangle(touching each other) and put the fourth one on top of them in the middle.

Pi  +  Rats  +  Caribbean

Pirates of the Caribbean

Take any 13 cards and flip them all. Rest 39 cards will make another pile. These two piles will have the same number of cards facing up. Why? Well, say out of those 13 selected cards are facing up.  Which means that in the pile with 39 cards there will be cards facing up. When you flip all 13 cards, number of cards facing up now becomes which is equal to what the other pile have.

MATHEMATICAL APPROACH-

Yes, the ant will reach the car. Calculus tells us exactly when:

if a < 0, then exp(c/a) < 1 and t < 0, which means no solution. The faster the car is, the greater [exp(c/a)]/c is and thus, the longer it is for the ant to reach the car.