Sticktoit Posted August 27, 2007 Share Posted August 27, 2007 What fractional part of the total surface area of cube C is red? (1) Each of 3 faces of C is exactly 1/2 red. (2) Each of 3 faces of C is entirely white. The OA is C. Shouldn’t it be A? Quote Link to comment Share on other sites More sharing options...
krusta80 Posted August 27, 2007 Share Posted August 27, 2007 What fractional part of the total surface area of cube C is red? (1) Each of 3 faces of C is exactly 1/2 red. (2) Each of 3 faces of C is entirely white. The OA is C. Shouldn’t it be A? (1) alone is INSUFF (2) alone is INSUFF (1) and (2) are SUFFICIENT A cube has 6 faces, and since each one can't be all white and 1/2 red at the same time, this accounts for all 6 faces. So, half of the faces are half red, so 1/4 of the total. Quote Link to comment Share on other sites More sharing options...
Sticktoit Posted August 28, 2007 Author Share Posted August 28, 2007 stmt 1) - = Surfaces colored in red / total surface area = (side ^ 2) + 1/2 (side ^ 2) / 6 (side ^ 2) I am not able to understand why stmt 1) is not sufficient. We have been given the information about the cells colored in red. Do we need to know about the remaining 3 faces... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.