Latest TCS Aptitude Question SOLUTION: There are 6 red balls,8 blue balls and 7 green balls in a bag. If 5 are drawn with replacement, what is the probability at least three are red?

• Placement Papers
• /
• TCS
• /
• Numerical Ability
• /
• Probability

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40115991) TCS Numerical Ability question Keep an EYE

There are 6 red balls,8 blue balls and 7 green balls in a bag. If 5 are drawn with replacement, what is the probability at least three are red?

Asked In TCS Emanuel Abhishek Murmu (9 years ago)

Unsolved Read Solution (5)

Is this Puzzle helpful?   (2)   (10) Submit Your Solution Probability

Read Solution (5) :

varsha agarwal  (8 years ago)

At least 3 reds means we get either : 3 red or 4 red or 5 red. And this is a case of replacement.
case 1 : 3 red balls : 6/21 x 6/21 x 6/21 x 15/21 x 15/21
case 2 : 4 red balls : 6/21 x 6/21 x 6/21 x 6/21 x 15/21
case 3 : 5 red balls : 6/21 x 6/21 x 6/21 x 6/21 x 6/21

Total probability = = (6/21 x 6/21 x 6/21 x 15/21 x 15/21)+(6/21 x 6/21 x 6/21 x 6/21 x (15 )/21)+ (6/21 x 6/21 x 6/21 x 6/21 x 6/21)
= 312/16807

Is this solution Helpfull? Yes (10) | No   

Nayanita saha  (8 years ago)

case 1=(r,r,r,b,g)=6/21 * 6/21 * 6/21 * 8/21 *7/21=
case 2=(r,r,r,r,b)=6/21 * 6/21 *6/21 * 6/21 * 8/21=
case 3=(r,r,r,r,g)=6/21 * 6/21 * 6/21 * 6/21 *7/21=
case 4=(r,r,r,r,r)=6/21 * 6/21 * 6/21 * 6/21 * 6/21=

Is this solution Helpfull? Yes (2) | No (1)  

BASAVARAJ H MUNDINMANI  (8 years ago)

(6c3*17c2+6c4*17c1+6c5)/21c5

Is this solution Helpfull? Yes (1) | No (1)  

Ananya Lawania  (8 years ago)

6c3 * 15c2+6c4 * 15c1+6c5/21c5

Is this solution Helpfull? Yes (1) | No   

Payel Das  (8 years ago)

Total balls =>21
n(S) => 21C5(as 5 balls are drawn) = 20349

Favourable Cases n(E) => 6C5 + 6C4*8C1 + 6C4*7C1 + 6C3*8C1*7C1 + 6C3*8C2 + 6C3*7C2 = 2331

Probability => n(E) / n(S) = 2331/20349 = 37/327 (ans.)

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.