The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Options:
(A) 18
(B) 16
(C) 17
(D) 19
(E) 13

Average of 20 numbers = 0
Sum of 20 numbers = (0 * 20) = 0
It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (-a). So the answer is: (D).

A telephone company needs to create a set of 3-digit area codes. The company is entitled to use only digits 2, 4 and 3, which can be repeated. If the product of the digits in the area code must be even, how many different codes can be created?
Options:
(A) 20
(B) 26
(C) 24
(D) 22
(E) 30

Total # of codes possible is 3*3*3 = 27. Oit of those 27 codes only the product of 333 will be odd, the remaining 26 will have either 2 or 4 in them, which ensures that their product will be even. Therefore the number of codes where the product of the digits is even = (total) - (restriction) = 27 - 1 = 26. So the answer is: (B).

Eddy and Freddy start simultaneously from city A and they travel to City B and City C respectively. Eddy takes 3 hours and Freddy takes 3 hours to complete the journey. If the distance between City A and City B is 600 kms and City A and City C is 300 kms. What is the ratio of their average speed of travel? (Eddy: Freddy)
Options:
(A) 2/1
(B) 3/8
(C) 8/5
(D) 5/8
(E) 5/3

Distance traveled by Eddy = 600 km
Time taken by Eddy = 3 hours
Average speed of Eddy = 600/3 = 200 km/hour
Distance traveled by Freddy = 300 km
Time taken by Freddy = 3 hours
Average speed of Freddy = 300/3 = 100 km/hour
Ratio of average speed of Eddy to Freddy = 200/100 = 2/1 So the answer is: (A).

A number is said to be prime saturated if the product of all the different positive prime factors of n is less than the square root of n. What is the greatest two digit prime saturated integer ?
Options:
(A) 99
(B) 98
(C) 97
(D) 96
(E) 95
A prime factors are 3 and 11. 33<sqrt(99)? no
B prime factors are 2 and 7. 14<sqrt(98)? no
C prime number. its sqrt is never greater than itself
D A prime factors are 2 and 6. 6<sqrt(96)? yes
E prime factors are 5 and 19. 45<sqrt(95)? no So the answer is: (D).