q: If a 3-digit integer is selected at random from the integers 700 through 899, inclusive, what is the probability that the second digit is one greater then the first digit, and the third digit is one greater than the second digit?
Options:
(A) 2/225
(B) 2/200
(C) 8/700
(D) 1/50
(E) 1/200
a: OK... Hundreds digit can be 7 or 8
If the hundreds digit is 7, then the tens digit has to be 8 and the units digit has to be 9
If the hundreds digit is 8, then the tens digit has to be 9 and the units digit has to be 10
A digit has to fall between 0 and 9, so 10 cannot be a digit
The number is 789
Total numbers between 700 and 899 = (899-700)+1 = 200
Probability = 1/200
The answer is (E).

q: The population of a bacteria colony doubles every day. If it was started 3 days ago with 3 bacteria and each bacteria lives for 12 days, how large is the colony today?
Options:
(A) 512
(B) 1024
(C) 768
(D) 2048
(E) 4096
a: OK... 9 days ago- 2
8 days ago- 4
7 days ago- 8
6 days ago- 16
5 days ago- 32
4 days ago- 64
3 days ago- 128
2 days ago- 256
Yesterday- 512
Today- 1024
The answer is (B).

q: Let us say that a table tennis tournament was going on with knock out terms which means the one who loses the match is out of the tournament. 55 players took part in that tournament. How many matches were played?
Options:
(A) 90 matches
(B) 95 matches
(C) 99 matches
(D) 85 matches
(E) 87 matches
a:
OK... A 54 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 54 matches were played.
The answer is (A).