# Thread: Logical Reasoning

1. Good post? |

## Logical Reasoning

A student is asked to pick marbles from a bag that contains 18 marbles. Eight marbles are red, 4 are green, and 6 are black. What is the minimum number of marbles that a blindfolded student would have to draw from the bag to be certain of having at least three marbles of the same color?
A) 5
B) 6
C) 7
D) 13
E) 14

Please post ur reasoning.

2. Good post? |
Ans : 7

There are 3 different colours.
To be certain that the student has selected atleast 3 marbles of same colour.
Assume that he has pciked up 1 from each box.
R G B
1 1 1
1 1 1
After picking up first 6 balls in that way. Now he will have 2 from each colour. The 7th ball of any colour will satisfy the condition of atleast 3 marbles of same colour.

3. Good post? |
C
Consider the worst case.
Say the person started picking ang got 2 Red, 2 Green and 2 Blues. The 7th pick will 100&#37; result in the condition "three marbles of the same color"

Is this correct ?

4. Good post? |
IMO C..

agree with Queen09 and venkat

5. Good post? |
C is the OA.
What i thought that it meant 3 of the same colour at one pick!
Then it becomes 14, which also happens to be an option (wrong one though).

6. Good post? |
Agree with Venkat's Reasoning, 7

7. Good post? |
1 red, 2 green, 2 blue, 2 red
7 ans