Solution:

19

Explanation:
The Cost of 1st Wizard is: 50 i.e Total coins spend: 50
The Cost of 2nd Wizard is: 100 i.e Total coins spend: 150
The Cost of 3rd Wizard is: 150 i.e Total coins spend: 300
The Cost of 4th Wizard is: 200 i.e Total coins spend: 500
The Cost of 5th Wizard is: 250 i.e Total coins spend: 750
The Cost of 6th Wizard is: 300 i.e Total coins spend: 1050
The Cost of 7th Wizard is: 350 i.e Total coins spend: 1400
The Cost of 8th Wizard is: 400 i.e Total coins spend: 1800
The Cost of 9th Wizard is: 450 i.e Total coins spend: 2250
The Cost of 10th Wizard is: 500 i.e Total coins spend: 2750
The Cost of 11th Wizard is: 550 i.e Total coins spend: 3300
The Cost of 12th Wizard is: 600 i.e Total coins spend: 3900
The Cost of 13th Wizard is: 650 i.e Total coins spend: 4550
The Cost of 14th Wizard is: 700 i.e Total coins spend: 5250
The Cost of 15th Wizard is: 750 i.e Total coins spend: 6000
The Cost of 16th Wizard is: 800 i.e Total coins spend: 6800
The Cost of 17th Wizard is: 850 i.e Total coins spend: 7650
The Cost of 18th Wizard is: 900 i.e Total coins spend: 8550
The Cost of 19th Wizard is: 950 i.e Total coins spend: 9500
The cost of 20th Wizard is: 1000 i.e Total coins spend: 10500 .... more than 10,000.

Solution:

20
Just count the nines in the numbers: 6, 16, 26, 36, 46, 56, 76, 86, 96, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69.
Note: 66 contains TWO nines

Solution:

One of the cop will move clockwise while the other will move anti-clockwise every day. In such a manner, they will catch the thief in minimum seven days.

Solution:

From top to bottom, the flavors are :

nutty-chocolate
peppermint
orange
Jamaica
walnut

Solution:

2, 3, 10 and 10
To maintain the difference of eight and keeping in mind the third and fourth hint, the first and third cards can be 2 and 10 or 10 and 2. But keeping in mind the first hint, we know that the first card is 2 and the third is 10. Similarly, if we see the fifth hint, the difference between the second and fourth card should be 7. Thus we know that the second card is 3 and the fourth card is 10.

Solution:

What is the correct time ?

Solution:

-3 -1 1

Explanation:
-3 * 1 * -1 = 3(prime)
-1 - (-3) = 1 -(-1) = 2

Solution:

I spoke with Joe.

Explanation:
There can be only two cases. Either Zoe is a liar or Joe is a liar.

First Case
Let us assume that Zoe is a liar and Joe is a truthful person.
If I asked the question from Joe, the answer will be yes. If I asked the question from Zoe, the answer will be no. Thus in this case, I must have asked from Joe.

Second Case
Let us assume that Zoe is a truthful and Joe is a liar.
If I asked the question from Joe, the answer will be yes. If I asked the question from Zoe, the answer will be no. Thus in this case as well, I must have asked from Joe only.

Solution:

Solution is below

Solution:

The Winchester brothers - sam and dean

Solution:

99 matches.

The number of matches will always sum up to one less than the number of players in a knock out tournament. You may calculate it in any manner. Thus 99 matches were played.