Twelve questions for Christoph!

Question 5 edited.

[ Question 1 ]

a, b, and c are integers. Is a+b+c=even?

1) a*b*c=even
2) a*c=odd


[ Question 2 ]

N is sum of reciprocal of 91 to100. Which one of the following is less than N?

a) 1/8
b) 1/9
c) 1/10


[ Question 3 ]

The radius of cylinder A is 3 and its height is 5. The radius of cylinder B is 5 and its height is 3. What is the difference between the volume of these two cylinders?


[ Question 4 ]

n is even. Which one of the following is even?

1) (n-1)(n+1)
2) (n+7)(n-2)


[ Question 5 ]

Christoph's friends pick 3 letters out of a, b, c, d, e, f, g, and h. They had to pick only 3 out of them, and 36 combinations are left over.
How many friends Christoph have?

(The order matters here. abc and acb are considered two different combinations.)

[ Question 6 ]

5 people do not have pets. 4 people have one pet each. 4 people have two pets each. 2 people have 3 pets each. Among those who have one pet, two people live in a same house, and the other two live in separate houses. How many houses have pets?


[ Question 7 ]

A transit company has a stastistics table as follow showing how many days it takes to deliver packages.

Transit days 1 2 3 4
No.of packages delivered 10 9 5 X

The average no. of transit days is 3 days, how many packages(X) need 4 days to deliver?


[ Question 8 ]

A farmer has a rectangular field that measures 1000 ft wide by 2000 ft long. There is an untillable strip 20 ft wide on the inside edges of the field. In addition, there is a 30 ft wide untillable strip bisects the field into two squares (approximate). Approximately what percentage of the field is tillable?


[ Question 9 ]

n is positive number. Is n^3>150?

1) (n-2)^3>25
2) (n-1)^3>75


[ Question 10 ]

The formular of calculating the total number of matches in a tournament game is G(n+1)=G(n)+n and G(2) = 1, where n stands for the number of people participating in the tournament. If 20 players are playing in the tournament, how many matches are there?

A. 180 B. 190 C. 200 D. 210 E. 220


[ Question 11 ]

Christoph is setting the table. He has 5 types of cheese and 2 types of fruits. In how many cases are the number of cheese and the number of fruits are same?


[ Question 12 ]

Is (a-5)^4 < (b-5)^4?

1) a<b
2) b-a<5