GRE Exam Numerical Ability Number System

How many different two-digit positive integers are there in which the tens digit is greater than 6 and the units digit is less than 4 ?
(A) 7
(B) 9
(C) 10
(D) 12
(E) 24

Read Solution (Total 3)

correct answer is = 12
(7,1) ,(7,2) ,(7,3) ,(8,1) ,(8,2), (8,3), (9,1), (9,2) , (9,3),(7,0),(8,0),(9,0)
7 years agoHelpfull: Yes(2) No(0)

(B) 9

With tens digit= 7,8,9 and Unit digit=1,2,3, total 9 combinations of two-digit are possible
(7,1) ,(7,2) ,(7,3) ,(8,1) ,(8,2), (8,3), (9,1), (9,2) & (9,3)
9 years agoHelpfull: Yes(0) No(2)
Let tenth digit be x and unit digit y
10x+6,y-4
then,difference between tenth digit and unit digit 16_4=12
7 years agoHelpfull: Yes(0) No(0)

GRE Other Question

Chris entered a number in his calculator and erroneously multiplied the number by 2,073 instead of 2.073, getting an incorrect product. Which of the following is a single operation that Chris could perform on his calculator to correct the error? Indicate all such operations.
(A) Multiply the incorrect product by 0.001
(B) Divide the incorrect product by 0.001
(C) Multiply the incorrect product by 1,000
(D) Divide the incorrect product by 1,000 A base of a triangle has length b, the altitude corresponding to the base has length h, and b 5 2h. Which of the following expresses the area of the triangle, in terms of h ?
(A) 1/2 * h^2
(B) 3/4 * h^2
(C) h^2
(D) 3/2 * h^2
(E) 2* h^2