Coordinate plane

BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

This topic has expert replies

Post new topic Post Reply

Previous Topic Next Topic

gmatblood: Master | Next Rank: 500 Posts; Posts: 489; Joined: Tue Jul 05, 2011 11:10 am; Thanked: 28 times; Followed by:5 members

Coordinate plane

by gmatblood » Sat Nov 05, 2011 9:37 am

Line l is defined by the equation y - 5x = 4 and line w is defined by the equation 10y + 2x + 20 = 0. If line k does not intersect line l, what is the degree measure of the angle formed by line k and line w? (Assume that all lines lie in one coordinate plane.)

0

30

60

90

It cannot be determined from the information given.

Quote

Source: Beat The GMAT — Data Sufficiency | Sat Nov 05, 2011 9:37 am

yasha_gmat: Junior | Next Rank: 30 Posts; Posts: 12; Joined: Sat Jul 24, 2010 11:10 am; Location: Bangalore, India; Thanked: 1 times

by yasha_gmat » Sat Nov 05, 2011 9:59 am

IMO D i.e 90

Line l and w are perpendicular.
And its given that line k does not intersect with line l.
So line k is also perpendicular to line w.

OA Please?

Quote

rijul007: Legendary Member; Posts: 588; Joined: Sun Oct 16, 2011 9:42 am; Location: New Delhi, India; Thanked: 130 times; Followed by:9 members; GMAT Score:720

by rijul007 » Sat Nov 05, 2011 10:17 am

Line l
y - 5x = 4
Slope = m1 = -1/-5 = 1/5

Line w
10y + 2x + 20 = 0
slope = m2 = -10/2 = -5

m1*m2 = -1
The two lines are Perpendicular

Line k does not intersect line l
line k is parellel to line l
hence, it too is perpendicular to line w.

Option D

Quote

gmatblood: Master | Next Rank: 500 Posts; Posts: 489; Joined: Tue Jul 05, 2011 11:10 am; Thanked: 28 times; Followed by:5 members

by gmatblood » Sat Nov 05, 2011 2:35 pm

Thanks a lot!!

m1*m2 = -1
The two lines are Perpendicular

Where can i find more such rules!!

Quote

satishchandra: Master | Next Rank: 500 Posts; Posts: 172; Joined: Fri Oct 21, 2011 9:10 pm; Thanked: 7 times; Followed by:2 members

by satishchandra » Sun Nov 06, 2011 1:30 am

gmatblood wrote: Where can i find more such rules!!

Refer the link below for many formulae
https://www.mathisfunforum.com/viewtopic.php?id=3301

Quote

vaibhavgupta: Master | Next Rank: 500 Posts; Posts: 416; Joined: Tue Aug 30, 2011 2:18 pm; Location: Delhi, India; Thanked: 13 times; Followed by:9 members

by vaibhavgupta » Sun Nov 06, 2011 4:31 am

gmatblood wrote:Line l is defined by the equation y - 5x = 4 and line w is defined by the equation 10y + 2x + 20 = 0. If line k does not intersect line l, what is the degree measure of the angle formed by line k and line w? (Assume that all lines lie in one coordinate plane.)

0

30

60

90

It cannot be determined from the information given.