Help! I have two days to the exam

mimi77 wrote:I have two questions from GMAT prep 2 exam that I need help with.

1. When a positive integer n is divided by 25, the reminder is 13, what is the value of n?

(1) n<100
(2) when n is divided by 20 the remainder is 3

the answer is C


Question 2.

In the XY plane, each point on circle K has non negative coordinates and the center of K is the point (4,7). What is the maximum possible area of K?

answer is 16pi

Can anyone explain how we get 16pi

thanks everybody

Q1)

Given n = 25q + 13

Statement 1) n < 100

So for different values of q - 0, 1, 2, 3 the value of n can be 13, 38, 63, 88

Statement 2) n = 20q + 13

So values of n are 23, 43, 63, 83

Ans is C as you can see the only common number between statement 1 and 2 is 63

Question 2)

Given all values of the circle have positive coordinates. So the circle is in the first quardent

Also given the centre of the circle is at 4, 7. That mean the maximum possible value of the radius is 4 (if it were 7 then the circle would extend outside the first quardent.

Area is pi r^2 which is 16 pi

(if u still dont understand it just draw it on a paper, with two lines extending from X = 4 and Y = 7 and then draw the biggest possible circle with that point as a mid point)

Best of luck with the exam

thanks ri2007 you are a life saver

thanks ri2007 you are a life saver