mathematics
This topic has expert replies
-
- Newbie | Next Rank: 10 Posts
- Posts: 6
- Joined: Tue Aug 22, 2017 7:46 am
- Thanked: 1 times
In a right-angled triangle, the hypotenuse is 39cm and the ratio of the other two sides is 12:5. Find the sides
GMAT/MBA Expert
- [email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi Diophantus,
One of the right-triangle 'patterns' that you will likely see on the GMAT is the 5/12/13. It's important to remember that MULTIPLES of this ratio are also valid right triangles. Thus, you could have sides of...
5, 12 and 13
10, 24 and 26
15, 36 and 39
Etc.
Here, we know that the hypotenuse is 39 and the ratio of the two 'legs' is 5:12. Thus, those two legs must be...
15 and 36
GMAT assassins aren't born, they're made,
Rich
One of the right-triangle 'patterns' that you will likely see on the GMAT is the 5/12/13. It's important to remember that MULTIPLES of this ratio are also valid right triangles. Thus, you could have sides of...
5, 12 and 13
10, 24 and 26
15, 36 and 39
Etc.
Here, we know that the hypotenuse is 39 and the ratio of the two 'legs' is 5:12. Thus, those two legs must be...
15 and 36
GMAT assassins aren't born, they're made,
Rich
GMAT/MBA Expert
- Jay@ManhattanReview
- GMAT Instructor
- Posts: 3008
- Joined: Mon Aug 22, 2016 6:19 am
- Location: Grand Central / New York
- Thanked: 470 times
- Followed by:34 members
Diophantus wrote:In a right-angled triangle, the hypotenuse is 39cm and the ratio of the other two sides is 12:5. Find the sides
Which side do you want? there are two sides...Diophantus wrote:In a right-angled triangle, the hypotenuse is 39cm and the ratio of the other two sides is 12:5. Find the sides
Say one of the sides is 12x and thus, the other one is 5x.
Thus, applying Pythagoras theorem, we get,
39^2 = (12x)^2 + (5x)^2
39^2 = 144x^2 + 25x^2
39^2 = 169x^2
Taking square root of both sides, we get
39 = 13x => x = 3
Thus, the two sides are 12*3 = 36 cm and 5*3 = 15 cm.
Pl. post a question with five options and the answer.
Hope this helps!
-Jay
Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide
_________________
Manhattan Review GMAT Prep
Locations: New York | Barcelona | Manila | Melbourne | and many more...
Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.