BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Pattern

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 32
Joined: Fri Feb 19, 2010 12:36 pm
Location: Pennsylvania
Thanked: 1 times

Pattern

by tsmith93 » Mon Mar 15, 2010 1:59 am
Ellie is dropping marbles into a box one at a time in the following order: red, white, white, blue, blue, blue; Red, white, white, blue, blue, blue; .... How many marbles will be in the box right after the 100th blue one is put in?
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 33
Joined: Tue Jan 19, 2010 11:15 pm
Location: India
Thanked: 2 times

by [email protected] » Mon Mar 15, 2010 2:10 am
After every 3 blue marbles there will be 2 white marbles and 1 red marble.

After every 9 blue marbles there will be 6 white marbles and 3 red marbles.

Similarily, after every 90 blue marbles there will be 60 white marbles and 30 red marbles.

So, after dropping 99 blue marbles there will be 66 white marbles and 33 red marbles.

After that one drops 1 red marble, 2 white marbles and 1 blue marble(the 100th blue marble)

So total = 100(blue) + 68(white) + 34(red) = 202 marbles :!:
Top
Post new topic Post Reply
• Page 1 of 1