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

Redeem

probablity

Expert replies
by cypherskull » Wed May 16, 2012 8:13 pm
What is the probability that 10 different numbers arranged linearly are in a strictly decreasing or increasing order?

a. 1/10!
b. 2/10!
c. 3/10!
d. 4/10!
Regards,
Sunit

________________________________

Kill all my demons..And my angels might die too!
Join the discussion
Source: — Problem Solving |

by aneesh.kg » Wed May 16, 2012 8:28 pm
cypherskull wrote:What is the probability that 10 different numbers arranged linearly are in a strictly decreasing or increasing order?

a. 1/10!
b. 2/10!
c. 3/10!
d. 4/10!
Hi Sunit,

Number of ways of arranging the ten numbers = 10!
Number of ways in which they are either in ascending or descending order
= 1 + 1 = 2

Therefore,
required probability = 2/10!
[spoiler](B)[/spoiler] is correct
Aneesh Bangia
GMAT Math Coach
[email protected]

GMATPad:
Facebook Page: https://www.facebook.com/GMATPad
Join the discussion