Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping

The no.s (a,b,c) are selected by throwing a dice thrice.then the probability that (a,b,c) are in A.P. is? i am geting the ans to be 18/216 but the ans is 21/216

The no.s (a,b,c) are selected by throwing a dice thrice.then the probability that (a,b,c) are in A.P. is?


i am geting the ans to be 18/216 but the ans is 21/216

Grade:11

3 Answers

Ashwin Muralidharan IIT Madras
290 Points
9 years ago

Hi Debadutta,

 

(a,b,c) can be

(1,2,3) -------- 2 possibilities (3,2,1) is the other order

(2,3,4) -------- 2 possibilities

.....     --------- -do-

.....

(4,5,6) -------- -do-

 

it could be

(1,3,5) -------- 2 possibilities

(2,4,6) -------- 2 possibilities

 

or it could be

(1,1,1)

(2,2,2)

....

....

(6,6,6).

 

So total number of ways = 2*6 + 6 = 18.

 

Your answer is very fine.

Have confidence in your working. It helps for competitive exam prearation.

21/216 is not the right answer.

 

Regards,

Ashwin (IIT Madras).

Sathya
35 Points
9 years ago

How can This be an A.P.Minimum C.D for an AP is 1.

(1,1,1) (2,2,2)........(6,6,6).

SIBASHIS MAHAPATRA
14 Points
9 years ago

the answar is  18/216, there cant be more than 18 combos of AP for 3 die

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free