Probability question

Question

There are 3 doors to a lecture room. In how many ways can lecturer enter the room from one door and leave from another door?

mayankdgmat · Answer

It should be 6. Select 3c1*2c1 = 6. Hope its clear

Themightyknight · Answer

enter from 1 - exit from 2
enter from 2- exit from 3
enter from 2 - exit from 1
enter from 2 - exit from 3
enter from 3 - exit from 1
enter from 3 - exit from 2

6?

americansad · Answer

To find the total number of ways to enter and leave from different doors, we multiply the number of choices for entering by the number of choices for exiting:

3 (choices for entering)×2 (choices for exiting)=6Thus, the number of ways the lecturer can enter from one door and leave from another is: 6

Nalkents · Answer

There are 3 choices (Door A, Door B, Door C). After choosing the entry door, there are 2 remaining doors to choose from for exiting.

ext{ (choices for entry)} 	imes 2 	ext{ (choices for exit)} = 6 	ext{ ways}
$$

Therefore, the lecturer can enter the room from one door and leave from another door in 6 different ways.

	Target Test Prep - Save up to $599 $400 Discount + $99 Bonus GMAT Club Tests
	e-GMAT: 60% Off on GMAT Focus Get to 735+ from any starting point
	Magoosh increases your score, guaranteed - 15% off ALL Magoosh GMAT plans with code GMATCLUB15 + Free GMAT Club Tests.
	Manhattan Prep: $99 Bonus Score Higher on Your GMAT Exam. Guaranteed.
	Experts' Global - ~~$1720~~ $960 End-to-End GMAT Prep + App Support: 150+ Videos, 2000+ Questions, 15 FLTs +
	GMATWhiz - $299 ~~$499~~ Experience the course through a free trial.
	GMAT Club Tests - Free Included with every course purchase of $149+ View all deals

Probability question

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards