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#1 2007-01-17 04:20:03

soha
Real Member
Registered: 2006-07-07
Posts: 2,530

Help Me Urgently

waveHELLO  EVERYONE.PLS HELP ME IN THIS PROBLEMdunno

A FATHER IS 30 TIMES OLDER THAN HIS SON.HOWEVER,18 YEARS LATER,HE WILL BEONLY THRICE ASOLD AS THE SON.WHAT IS THE FATHER 'S PRESENT AGE.

PLS HELP ME URGENTLY.


"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!" smile smile
- David O. McKay

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#2 2007-01-17 04:37:34

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

Re: Help Me Urgently

You can derive this equation:

Let X = Father's age
Let Y = Son's age

1. x = 30y
2. x+18=3(y+18)

Substitute 1 into 2 to get

30y+18=3(y+18)

Solve for y, then substitute the y value into eq.1

Last edited by Toast (2007-01-17 04:43:16)

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#3 2007-01-17 04:46:55

soha
Real Member
Registered: 2006-07-07
Posts: 2,530

Re: Help Me Urgently

Cant Under Stand.please Explain Briefly


"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!" smile smile
- David O. McKay

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#4 2007-01-17 04:51:11

Toast
Real Member
Registered: 2006-10-08
Posts: 1,321

Re: Help Me Urgently

You know that the father is presently 30 times older than his son, so
1. x = 30y
You also know that in 18 years time he will be 3 times as old as his son
2. x+18=3(y+18)
(You have to add 18 years to x and to y)

Since x = 30y
You can substitute x into equation 2:
30y+18=3(y+18)
30y+18=3y+54
27y=36
y=1.3333...
Hence the son is presently 1 and 1/3 years old

Since y = 1.3333...
x = 30(1.333...)
x = 40
Hence the father is presently 40 years old.

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