There are 23 distinct numbers in set M, there are 28 distinct numbers in set N, and there are 12 distinct numbers that are in both sets M and N. Set H is the set containing the elements that are in at least one of sets M and N. How many elements are in set H?
Options:
(A) 39
(B) 40
(C) 51
(D) 58
(E) 63

{Total} = {M} + {N} - {Both}
{Total} = 23 + 28 - 12 = 39. So the answer is: (A).

From a Group of 10 People, Including George and Nina, 3 people are to be selected at random to work on a certain project. What is the probability that 3 people selected will include George but not Nina
Options:
(A) 5/56
(B) 9/56
(C) 28/120
(D) 21/56
(E) 25/56

Number of ways of selecting 3 people out of 10 people = 10C3
In the three members George will always be there in the team. At this step we have vacancy for 2 more members and 9 members are available. Lina cannot be there in the team. So 2 members have to be selected and the number of available members = 9 - Nina = 8
Number of ways to form a 3 member team that includes George and excludes Nina = 8C2
Probability = 8C2/10C3 = 28/120 So the answer is: (C).

At what rate percent on simple interest will a sum of money double itself in 30 years?
Options:
(A) 3 1/3%
(B) 3 1/8%
(C) 3 7/3%
(D) 3 1/7%
(E) 3 1/1%

P = (P*30*R)/100
R = 3 1/3% So the answer is: (A).

At what rate percent on simple interest will a sum of money double itself in 30 years?
Options:
(A) 3 1/3%
(B) 3 1/8%
(C) 3 7/3%
(D) 3 1/7%
(E) 3 1/1%
P = (P*30*R)/100
R = 3 1/3% So the answer is: (A).