It is currently 23 Nov 2017, 06:07

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 4354

Kudos [?]: 3058 [0], given: 0

GPA: 3.82
A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th [#permalink]

### Show Tags

22 Nov 2016, 01:41
Expert's post
1
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

79% (01:17) correct 21% (01:08) wrong based on 53 sessions

### HideShow timer Statistics

A triangle’s area is S=$$\sqrt{( p(p-a )(p-b )(p-c))}$$, where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6
[Reveal] Spoiler: OA

_________________

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.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself

Last edited by MathRevolution on 24 Nov 2016, 18:26, edited 1 time in total.

Kudos [?]: 3058 [0], given: 0

SVP
Joined: 12 Sep 2015
Posts: 1851

Kudos [?]: 2625 [0], given: 362

Re: A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th [#permalink]

### Show Tags

22 Nov 2016, 07:39
Expert's post
Top Contributor
MathRevolution wrote:
A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6

You're missing a few key variables in your Heron's Law formula.
S=√[(p)(p-a)(p-b)(p-c)], where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2
_________________

Brent Hanneson – Founder of gmatprepnow.com

Kudos [?]: 2625 [0], given: 362

Senior CR Moderator
Status: Long way to go!
Joined: 10 Oct 2016
Posts: 1255

Kudos [?]: 1015 [0], given: 61

Location: Viet Nam
Re: A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th [#permalink]

### Show Tags

22 Nov 2016, 08:11
MathRevolution wrote:
A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6

Heron's formula:
$$S=\sqrt{p(p-a)(p-b)(p-c)}$$ with $$p=\frac{a+b+c}{2}$$

a=5, b=6, c=7 then $$p=\frac{5+6+7}{2}=9$$

$$S=\sqrt{9 \times (9-5) \times (9-6) \times (9-7)}=\sqrt{9 \times 4 \times 3 \times 2}=\sqrt{6^2 \times 6}=6\sqrt{6}$$

_________________

Kudos [?]: 1015 [0], given: 61

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 4354

Kudos [?]: 3058 [0], given: 0

GPA: 3.82
Re: A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th [#permalink]

### Show Tags

24 Nov 2016, 02:46
==> If you substitute p=(5+6+7)/2=9 into S=$$\sqrt{√(p(p-a)(p-b)(p-c))}$$, it becomes S=$$\sqrt{(9*4*3*2)}$$=6√6. Therefore, the answer is C.

_________________

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.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself

Kudos [?]: 3058 [0], given: 0

Manager
Joined: 12 Jun 2016
Posts: 229

Kudos [?]: 42 [0], given: 145

Location: India
WE: Sales (Telecommunications)
Re: A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th [#permalink]

### Show Tags

27 Oct 2017, 10:36
Hello Modertors/MathRevolution

The highlighted part of the question stem is incorrect here. It is not possible to get the answer with whats written. Please take and look and correct the same.

MathRevolution wrote:
A triangle’s area is S=$$\sqrt{( ((p-) )(p-) )(p-c))}$$, where a, b and c are the three side lengths of the triangle and p=(a+b+c)/2. When a=5, b=6 and c=7, what is the area of the triangle?

A. 4√6 B. 5√6 C. 6√6 D. 7√6 E. 8√6

_________________

My Best is yet to come!

Kudos [?]: 42 [0], given: 145

Re: A triangle’s area is S=√( ((p-) )(p-) )(p-c)), where a, b and c are th   [#permalink] 27 Oct 2017, 10:36
Display posts from previous: Sort by