Jump to content
BrainDen.com - Brain Teasers
  • 0
Sign in to follow this  
Guest

How Old Are They Now?

Question

Guest

Eight years ago, Verizon Wireless was half as old as Sprint will be when Sprint is one year older that AT&T will be five times as old as AT&T will be two years from now.

Ten years from now AT&T will be twice as old as Sprint was when Verizon Wireless was nine times as old as AT&T

When AT&T was one year old, Verizon Wireless was three years older than AT&T will be when Sprint is three years older than AT&T will be when Sprint is there times as old as Verizon Wireless was six years before the time when Sprint was half as old as AT&T will be when Verizon Wireless will be ten years older than Verizon Wireless was when Sprint was one-third as old as AT&T will be when Verizon Wireless will be three times as old as it was when Sprint was born.

How old are they now?

Share this post


Link to post
Share on other sites

5 answers to this question

  • 0

Ages now: AT&T=A; Sprint=S; Verizon Wireless=V.

Eight years ago, Verizon Wireless was

half as old as Sprint will be when Sprint is

one year older that [than?] AT&T will be [when it is?]

five times as old as AT&T will be two years from now.

[V-8] = 1/2 [1 + 5*(A+2)]

Ten years from now AT&T will be

twice as old as Sprint was

when Verizon Wireless was nine times as old as AT&T let x satisfy [V-x] = 9[A-x]

[A+10] = 2[s-x]

When AT&T was one year old, let u satisfy [A-u] = 1

Verizon Wireless was three years older than AT&T will be let z satisfy [V-u] = 3 + [A+z]

when Sprint is three years older than AT&T will be let w satisfy [s+z] = 3 + [A+w]

when Sprint is there [three?] times as old as Verizon Wireless was let y satisy [s+w] = 3[V-y]

six years before the time when Sprint was half as old as AT&T will be let q satisfy [s-(6+y)] = 1/2[A+q]

when Verizon Wireless will be ten years older than Verizon Wireless was let t satisfy [V+q] = 10 + [V-t] -> q = 10-t

when Sprint was one-third as old as AT&T will be let m satisfy [s-t] = 1/3[A+m]

when Verizon Wireless will be three times as old as it was when Sprint was born. [V+m] = 3[V-S] -> m= 2V-3S

How old are they now?

Eleven variables: A, S, V, x, u, z, w, y, q, t, m

Eleven equations:

[ 1] 2[V-8] = 1 + 5[A+2]

[ 2] V-x = 9[A-x]

[ 3] A+10 = 2[s-x]

[ 4] A-u = 1

[ 5] V-u = 3 + A+z

[ 6] S+z = 3 + A+w

[ 7] S+w = 3[V-y]

[ 8] 2[s-6-y] = A+q

[ 9] q=10-t

[10] 3[s-t] = A+m

[11] m = 2V-3S

piece of cake.

Back later with the solution.

If you're reading this and this is the latest post, have a crack at them.

Share this post


Link to post
Share on other sites
  • 0

Wondering what happened to the spoiler tag in previous post, and why I can't edit it to fix. :o

First statement in OP is not a well formed sentence, so it's meaning is not certain.

Eight years ago, Verizon Wireless was half as old as Sprint will be when Sprint is one year older that AT&T will be five times as old as AT&T will be two years from now
So the 11 equations in previous post are uncertain as well.

They reduce to


13A -8S -V = -40
6A -16S +8V = -60
5A	 - 2V = -27

which have the unlikely solutions

S = 64/11

A = 21/11

V = 201/11

Which is where I'll leave it, as I have dinner to eat. It's solved in principle.

Which is to say,

A, S and V are correct, [but the constants may be wrong] ;)

Share this post


Link to post
Share on other sites
  • 0
Wondering what happened to the spoiler tag in previous post, and why I can't edit it to fix. :o

the spoiler was used incorrectly (no ending spoiler tag)

re second issue, I have disabled editing posts after 10 minutes

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×