Solution:

Just 1

Solution:

What

It stated 'WHAT' was the father's name.

Solution:

18 x 12 ÷ 2 + 3 = 111

Solution:

mistaken

Solution:

We can calculate out how many days there will be for the 13th on each month if we count from the beginning of the year (January 1). Then we divide total days by 7 to get the remainders. We also need to consider the leap year. Through the whole year we had all kinds of remainders, from 0 to 6. The minimum of occurence for all the unique remainders was 1. It means that we have at least one Friday on 13th. In a regular year, the best chance you can get 3 Fridays on 13th, which are in February, March and December because the remainders of these 3 months are 2. In a leap year, the best chance you also can get 3 Fridays on 13th, which are in January, April and July because the remainders of these 3 months are 6.

Solution:

5625

n^1
75 * 75 = 5625 (sum of first 75 odd numbers).
50 * 50 = 2500 (sum of first 50 odd numbers).

Solution:

The mathematician made a small fence around himself and declared himself to be on the outside.

Solution:

21, 28.

They are the numbers that either contain the digit 7 or are divisible by 7.

Solution:

Place 1 white marble in one bowl, and place the rest of the marbles in the other bowl (49 whites, and 50 blacks).

This way you begin with a 50/50 chance of choosing the bowl with just one white marble, therefore life! BUT even if you choose the other bowl, you still have ALMOST a 50/50 chance at picking one of the 49 white marbles.

Solution:

A lion, king of the jungle! (the head of a Lamb, the middle of a pIg, the hind of a buffalO and the tail of a dragoN)