ST Alpha - "From B2: b. is too kind a grader. I would've docked you all for not showing your work. spoilers" (Reading a Post)

SlickerTalk
Search Archives
The Leaderboard
The FAQ

Down to Post

Backboards:

Posts: 154

From B2: b. is too kind a grader. I would've docked you all for not showing your work. spoilers

Posted by Oswaldo MoBarony (aka BaronWasteland) Jan 14 '16, 15:50

There are 13 red balls and 30 non-red balls.
Proportion of red balls = 13/(13+30) = 13/43

Let x = the number of red balls added to the jar.
Proportion of red balls now = P = (13+x)/(43+x).

Require P >= 2/3.
(13+x)/(43+x) >= 2/3.
3*(13+x) >= 2*(43+x).
39 + 3x >= 86 + 2x
x >= 47.

Show Spoilers

Responses:

good job! Will showed part of his work. you made it way more complicated than I did, heh. - b. Jan 14, 16:03 4
- In an alternate universe, I am the high school math teacher who you like only in restrospect because he challenged you. -- nm - Oswaldo MoBarony Jan 14, 16:16 3
  - no offense, but more like the college one who made me stop taking higher math classes. - b. Jan 14, 16:23 1
    - I aspired to be that guy at one point! - Oswaldo MoBarony Jan 14, 17:18
  - aka reagen -- nm - slipping jimmy Jan 14, 16:19
nice -- nm - prayformojo Jan 14, 15:55

Post a message top

From B2: b. is too kind a grader. I would've docked you all for not showing your work. spoilers

Replies are disabled on threads older than 7 days.