A jar contains 20 marbles: 4 red, 6 white and 10 blue. If you remove

Corrected .

Minimum required to be sure = 10 blue + 6 white + 2 red = 18

We have 10 Blue, 6 White, and 4 Red marbles.
We have to certainly remove a minimum of 2 numbers of marbles of each color.
I will go by options:-
A. Remove 6: Chances are there, you may choose 6 whites. --->No Red ,No Blue.......... DISCARD
B. Remove 10: Chances are there, you may choose 10 blue.--->No Red ,No White.......... DISCARD
C. Remove 12: Chances are there, you may choose 10 blue & 2 White.--->No Red.......... DISCARD
D. Remove 16: Chances are there, you may choose 10 blue & 6 White.--->No Red.......... DISCARD
E. Remove 18: Chances are there, you may choose 10 blue(fully taken), 6 White(fully taken), and 2 Red(its automatic).--->Each marbles at a minimum of 2 numbers.......... (This is the answer)

Ans. (E)

Total Marble : 20

Red: 4

White: 6

Blue: 10

Note: 2 Marbles of each color ( At least )

For this kinda question Back solving Strategy is the best.

A) 6.........................All 6 can be white

B) 10.............All 10 can be blue

C) 12............( 10 blue + 2 white). Here no red.

D) 16............(10 blue + 6 white) Here no red.

E) 18............( 10 + 6 + 2). This is the option where we are compelled to pick up All the marbles and minimum 2 marbles of each color.

The best answer is E.

We must remove at least 18 marbles to guarantee we have at least 2 marbles of each colour. That is because if we remove 17 marbles, it’s possible that we have 10 blue, 6 white and 1 red marbles, and we don’t have 2 marbles of each colour. However, if we remove one more marble and since that marble must be red, we have (at least) 2 marbles of each colour.

Answer: E

chetan2u I did not even understand what the question wants us to do?
It went up above my head.!!
How does removing 18 marbles leave 2 marbles of each color as asked in the question? (highlighted in the red color)

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.