GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 23 Jan 2020, 11:19

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# If a right triangle has 2x and 2x+1, what is the length of BC, in term

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 8445
GMAT 1: 760 Q51 V42
GPA: 3.82
If a right triangle has 2x and 2x+1, what is the length of BC, in term  [#permalink]

### Show Tags

21 Feb 2016, 22:05
00:00

Difficulty:

15% (low)

Question Stats:

80% (00:58) correct 20% (01:13) wrong based on 54 sessions

### HideShow timer Statistics

Attachment:

a right triangle.jpg [ 5 KiB | Viewed 944 times ]

If a right triangle has 2x and 2x+1, what is the length of BC, in terms of x?

A. 4x-1
B. 4x+1
C. √(4x-1)
D. √(4x+1)
E. 4x

* A solution will be posted in two days.

_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $79 for 1 month Online Course" "Free Resources-30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons - try it yourself" Director Joined: 20 Feb 2015 Posts: 731 Concentration: Strategy, General Management Re: If a right triangle has 2x and 2x+1, what is the length of BC, in term [#permalink] ### Show Tags 22 Feb 2016, 06:50 using pythagoras theorem we have (BC)2 =(AC)2-(AB)2 BC = root(4x+1) Manager Joined: 09 Jul 2013 Posts: 107 If a right triangle has 2x and 2x+1, what is the length of BC, in term [#permalink] ### Show Tags 22 Feb 2016, 10:29 CounterSniper wrote: using pythagoras theorem we have (BC)2 =(AC)2-(AB)2 BC = root(4x+1) CounterSniper nailed it. Here it is with the proper formatting: $$(AC)^2 = (AB)^2 + (BC)^2$$ $$(2x+1)^2 = (2x)^2 + (BC)^2$$ $$4x^2 + 4x+ 1 = 4x^2 + (BC)^2$$ $$(BC)^2 = 4x+1$$ $$BC = \sqrt{4x+1}$$ Answer: D _________________ Dave de Koos GMAT aficionado CEO Joined: 20 Mar 2014 Posts: 2548 Concentration: Finance, Strategy Schools: Kellogg '18 (M) GMAT 1: 750 Q49 V44 GPA: 3.7 WE: Engineering (Aerospace and Defense) If a right triangle has 2x and 2x+1, what is the length of BC, in term [#permalink] ### Show Tags 22 Feb 2016, 10:51 davedekoos wrote: CounterSniper wrote: using pythagoras theorem we have (BC)2 =(AC)2-(AB)2 BC = root(4x+1) CounterSniper nailed it. Here it is with the proper formatting: $$(AC)^2 = (AB)^2 + (BC)^2$$ $$(2x+1)^2 = (2x)^2 + (BC)^2$$ $$4x^2 + 4x+ 1 = 4x^2 + (BC)^2$$ $$(BC)^2 = 4x+1$$ $$BC = \sqrt{4x+1}$$ Answer: D An alternate way would be to substitute x=1 to get the 2 given sides as 2x=2 units and 2x+1=9, giving you the other side = $$\sqrt{9-4}$$ = $$\sqrt{5}$$ Analyse options, A. 4x-1 = 3 . Eliminate B. 4x+1 = 5. Eliminate C. √(4x-1) = $$\sqrt{3}$$. Eliminate D. √(4x+1) =$$\sqrt{5}$$. Keep. E. 4x= 4. Eliminate. Thus D is the correct answer. Hope this helps. Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 8445 GMAT 1: 760 Q51 V42 GPA: 3.82 Re: If a right triangle has 2x and 2x+1, what is the length of BC, in term [#permalink] ### Show Tags 23 Feb 2016, 18:35 If a right triangle has 2x and 2x+1, what is the length of BC, in terms of x? A. 4x-1 B. 4x+1 C. √(4x-1) D. √(4x+1) E. 4x -> (2x)2+(BC)2=(2x+1)2, (BC)2=4x2+4x+1-4x2=4x+1, BC=√(4x+1). Therefore, the answer is D. _________________ MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Re: If a right triangle has 2x and 2x+1, what is the length of BC, in term   [#permalink] 23 Feb 2016, 18:35
Display posts from previous: Sort by