Ultimate Quant Marathon Blog For IIM CAT

For All Your Quant Queries

Problem Of The Week 24

with 6 comments


Let x,y be positive integers such that 19x+90+8y=1998. Let a be the max value of x and b  the max of y.

Find a+b.

Written by Implex

September 23, 2008 at 12:49 am

6 Responses

Subscribe to comments with RSS.

  1. x = 100 y = 41

    a+b=141

    marijuana

    September 23, 2008 at 2:44 am

  2. Sorry! The answer is :: 229 for x =100 and y = 229

    i used the funda ::

    ax+by = k

    Get any value of (x,y) which satisfies the equation and then the next solution i.e x1,y1 is (x +- coeff of y ) (y+- coeff of x)

    here x will decrease by 8 and y will increase by 19.

    the last value which wud satisfy is x=4 and y = 229

    Regards!

    marijuana

    September 23, 2008 at 2:54 am

  3. 329

    bOOn

    September 23, 2008 at 7:33 am

  4. yupp 329 is righlty done
    100 is easy
    229 is just a bit more🙂

    outtimed

    September 23, 2008 at 11:24 am

  5. Can somebody explain how the correct answer is 329 ?

    riya

    September 23, 2008 at 7:00 pm

  6. Riya its pretty simple
    for x max can be easily found to be 100
    as 1900+90+8=1998
    now case 2
    19x+90+8y=1998
    as all terms are even so is x
    we check for x=2 does not give integer y
    we check for x=4 gives y=229

    we are done here

    outtimed

    September 23, 2008 at 7:09 pm


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: