If four numbers are randomly selected without replacement from set {1,

Question

If four numbers are randomly selected without replacement from set {1, 2, 3, 4}, what is the probability that the four numbers are selected in ascending order?

A. 1/256
B. 1/64
C. 1/48
D. 1/24
E. 1/12

chetan2u · Accepted Answer

total ways to arrange four numbers = 4*3*2*1=4!=24
ways to arrange four numbers in ascending order= 1 way only..
prob = 1/24.. ans D

Lucky2783 · Answer

there is only one way to select in ascending order . 1,2,3,4

\frac{1}{4} *\frac{1}{3} * \frac{1}{2} = \frac{1}{24}

Answer D.

hsbinfy · Answer

Answer is D

total number of cases for selecting four numbers=4*3*2*1

case for ascending order=1(1,2,3,4)

req prob =1/4!
=1/24

Bunuel · Answer

MAGOOSH OFFICIAL SOLUTION: ascendingorder.png

SavageBrother · Answer

If four numbers are randomly selected without replacement from set {1, 2, 3, 4}, what is the probability that the four numbers are selected in ascending order?

A. 1/256
B. 1/64
C. 1/48
D. 1/24
E. 1/12

4 out of 1,2,3,4; chance = 1/4
3 out of 1,2,3; chance = 1/3
2 out of 1,2; chance = 1/2
1 out of 1; chance = 1

1/4 * 1/3 * 1/2 * 1
1*1*1*1 = 1
4*3*2*1 = 24

1/24.

D.

OptimusPrepJanielle · Answer

1st number (i.e. 1) can be selected out of 4 numbers in 4 ways. 2nd number (i.e. 2) can be selected out of 3 numbers in 3 ways. 3rd number (i.e. 3) can be selected out of 2 numbers in 2 ways. 4th number (i.e. 4) can be selected out of 1 numbers in 1 ways. Total number of ways = 4*3*2*1 = 24 ways. Hence probability = 1/24 Hence option (D). -- Optimus Prep's GMAT On Demand course for only $299 covers all verbal and quant. concepts in detail. Visit the following link to get your 7 days free trial account: https://www.optimus-prep.com/gmat-on-demand-course

FB2017 · Answer

At a time we select one number.
Total outcomes =4*3*2*1=24  .
So probability they are in ascending order will always be 1/24.
Option D.

aragonn · Answer

If we pick all four numbers in ascending order, that means that we select number 1 first and then number 2 second and then number 3 third and then number 4 last. So we need to calculate the individual probabilities of these events (taking into account the fact that there is NO replacement between selections), and then multiply them all together. For example, for the probability of selecting the 1 first, there's a 1 in 4 chance of selecting a 1 on the first draw. That 1 is then removed from the pool of numbers, leaving {2, 3, 4}. There is now a 1 in 3 chance of selecting the 2 from those three numbers. And so on.

Here is the math:

P(all four numbers in ascending order) =
P(1first AND 2second AND 3third AND 4fourth) =
P(1first) * P(2second) * P(3third) * P(4fourth) =
1/4 * 1/3 * 1/2 * 1 =
1/24

Here is the math:

P(all four numbers in ascending order) = 
P(1first AND 2second AND 3third AND 4fourth) =
P(1first) * P(2second) * P(3third) * P(4fourth) =
1/4 * 1/3 * 1/2 * 1 = 
1/24

JeffTargetTestPrep · Answer

There are 4! = 24 arrangements of the numbers 1, 2, 3, 4. Only one arrangement is in ascending order: 1, 2, 3, 4. Therefore, the probability is 1/24.

Answer: D

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If four numbers are randomly selected without replacement from set {1,

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