PS 13

[magical cook]

If the average (arithmetic mean) of x, y, and 20 is 10 greater than the average of x, y, 20,
and 30, what is the average of x and y?
A. 40
B. 45
C. 60
D. 75
E. 95

Hi, Answer seems to be wrong for thsi question, so can anyone confirm?

[sujaysolanki]

My bad ,,thnks for the correction guys ..
E it is

[projase]

If the average (arithmetic mean) of x, y, and 20 is 10 greater than the average of x, y, 20,
and 30, what is the average of x and y?
A. 40
B. 45
C. 60
D. 75
E. 95

Hi, Answer seems to be wrong for thsi question, so can anyone confirm?

(x+y+20)/3 = 10 + (x+y+20+30)/4
4x+4y+80 = 120 + 3x+3y+150
x+y=120+150-80=190
(x+y)/2= 95
Answer is E

[Suyog]

agree with Projase.

I wud solve this by substituting the ans values if i cudn't form the equation.
Here only 95 gives possible solution.

Since avg is 95, addition of x & y is 190.

avg of x, y & 20 = 70
and avg of x,y,20 & 30 = 60

Ans E

[magical cook]

Hi, I though A as well but the answer is B (which I think is wrong...)

10 greater than should be expressed Aaverage - Baverage = 10 OR Aaverage = 10 + Baverage.....

Maybe gabriel will come figure it for us...