Find the number

[Abhishek009]

A cool Maths problem from my end ? Try to solve it.

 

A two-digit number, read from left to right, is 4.5 times as large as

the same number read from right to left.

What is the number?

[sjmit4]

It is "81"

 

as 18*4.5= 81..

[Abhishek009]

It is "81"

 

as 18*4.5= 81..

 

 

Yeah absolutely correct.

 

 

Here is the logic :

 

From left to right you read the number as :

 

10a + b

 

From right to left you will read the number as :

 

10b + a

 

Now according to the problem :

 

9/2 (10a + b ) = 10b +a

 

90a + 9b = 20b + 2a

 

So 88a = 11 b

 

Thus 8a = b

 

Now the hundredths digit is 8 times the units digit.

 

Find out the possible values. a is only 1

 

and hence b = 8

 

 

Thus you get it now : the number from left to right is 8*10 + 1 = 81.

 

 

Hope it helps.

Edited August 17, 2010 by Abhishek009