A cave is going to explode. A family is trapped inside that cave. The only way to get outside is a narrow tunnel. But the tunnel is weak and thus only two people can go at one time. Also, everybody is afraid of going alone.
The father takes one minute to go through till the end, the mother takes two, the son takes four and the daughter takes five. The cave and tunnel will explode in twelve minutes. Can they make it to the other end in that time frame?
PS: Keep in mind that when two people are moving, the total time taken will be as per the slower one.
Choose the correct choice:
A) 10 minutes  B) 12 minutes  C) 18 minutes  D) 19 minutes  E) 16 minutes
B   12 minutes   Explanation:   Yes, surely they can all make it out of the cave.   First, father and mother will go. Time taken = 2 minutes.   Father comes back. Time taken = 2 + 1= 
<gadget id="calculator">2 + 1</gadget>
<output>3</output>
3 minutes.   Both children go. Time taken= 3 + 5= 
<gadget id="calculator">3 + 5</gadget>
<output>8</output>
8 minutes.   Mother comes back. Time taken= 8 + 2= 
<gadget id="calculator">8 + 2</gadget>
<output>10</output>
10 minutes.   Mother and Father go. Time taken= 10 + 2= 
<gadget id="calculator">10 + 2</gadget>
<output>12</output>
12 minutes.   Thus in 12 minutes, all of them will be out of the cave through the tunnel.
<result>B</result>
A cave is going to explode. A family is trapped inside that cave. The only way to get outside is a narrow tunnel. But the tunnel is weak and thus only two people can go at one time. Also, everybody is afraid of going alone.
The father takes one minute to go through till the end, the mother takes two, the son takes four and the daughter takes five. The cave and tunnel will explode in twelve minutes. Can they make it to the other end in that time frame?
PS: Keep in mind that when two people are moving, the total time taken will be as per the slower one.