Answer- I suggest Jacob to play second

Explanation: The options to get 15 are at most 5 digits long (1+2+3+4+5). So for ever number John starts Jacob will be able to block him from getting to 15 (on the 4th digit pickup or the 6th digit pickup)

For example: 9 for John 6 to Jacob if 5 to John than 1 (4th dight chosen) to Jacob or (4 and 2) or (3 and 2) and if John starts with a small number then Jacob can choose a big number which will force John to block him so the real control on the game flow is Jacob

47. The worst case is that we take first 10 socks of different colors than we take 1 red and 3 yellow and 8 of each different color. So now we have one pair of each color. We repeat it 3 more times so now we have two pairs of each color + 1 sock of a pair from each color. So now we take only one sock and we are sure we have 3 pairs of the same color. Total 10+4+4*8+1 = 47

answer is 65292. Explanation: Since the 4th digit is 4 greater than the second digit, and the 3rd digit is 3 less than the 2nd digit  we have only 2 options for the 2nd-4th digits: 529 and 418. To get 11 from 2 digits it can be 9+2, 8+3 , 7+4 , 6+5.  If we look on the 2nd option 418 we can see that that if (without taking in consideration the fact that the 1st digit is thrice the last digit) choose the combination of 34183 or 74183 we will get only 2 combinations of 11. So 418 in the middle is not possible. So we are left with 529. So since the 1st digit is thrice the last digit it gives us 3,1 or 6,2 or 9,3. The only possible choice is 6,2 because the other 2 options will not give us that there are 3 pairs whose sum is 11. (35291 will give one pair and 95293 will give 2 pairs)

If only 4 people make a cut than they should cut it horizontally. 4 cuts will give us 5 pieces!! and if the height of each piece is the same  then  everyone gets a 1/5th of piece.

The numbers are 3 & 4
Explanation: If the sum was 4 (2+2) or  5(2+3) Sam would  know the answer immediately. If the sum was 6 (2 &4 , 3 & 3), Pete would  know the answer immediately because the product is 8 or 9 which has only one combination. So if the sum is 7 (2+5, 3+4), Sam doesn’t know the answer but is is was 2 & 5 Pete would know because the product is  10. So since he doesn’t know he has 12 so he can say he does not know the answer and also know that Sam also does not know. So that how Sam now knows the answer/

He halved the pills so that the halves are arranged half top and half bottom, and than he takes  all the halves of each pill.

Choose the “Death from electric chair” because as mentioned  at the beginning :  You’re in a mansion and the power’s out!!

The max number of pieces by 4 cuts is 16 on a round cake.   If we make two cuts from top to bottom we get 4 pieces. now if we cut from right to left we will get 8 pieces. If we made 3 cuts at the 1st step we will get at the 2nd step 12 pieces but we can take all the 8 pieces and put them in a row or one over the other and then make the 3rd cut.

9 worst case because when 5 pineapple and 3 strawberries are  chosen we don’t have any mango..

The third room. The lions are already dead. They can’t survives 3 years without food