This is yet another problem on the sample 7th grade EOG test.

Shana and Mina are workign on a math project and will receive the same grade. Their individual grades before the project are listed below.

What grade could they receive that will keep Shana's average the same, but improve Mina's average by one point?

A) 83

B) 85

C) 87

D) 90

I worked this problem last night and I got D) 90, but I had to go thru all the possible answers before I got to the right answer. My question is, is there any short cut, or this the only way to solve a problem like this?

_________________

I also have another problem that's similar, but I'm unable to figure it out:

Charlie and Daniel are playing darts. The winner will be the one wtih the highest average score after 6 games. Charlie ahs completed 6 games and has an average score of 190. So far, Daniel has played 5 games and has an average score of 183. What score does Daniel need in his final game to have the same average score as Charlie?

A) 190 points

B) 197 points

C) 225 points

D) 270 points

How do I begin to tackle this? I figure it's got to be simple b/c it's on a 7th grade test. I think?