A number x is equal to 6 less than twice of a number y formed by taking the digits of the number x

M4maths Previous Puzzles

22 Apr 2010 Find the Number

A number x is equal to 6 less than twice of a number y formed by taking the digits of the number x in reverse order.
The number x is

OPtion

1) 65
2) 24
3) 26
4) 68
5) 84
6) 48
7) 86
8) 62
9) 56
10) 42

Solution

Let the number x is 10a + b then y = 10b + a,
Given that 10a + b = 2 (10b + a) – 6
Or 10a + b = 20b + 2a – 6
Or 8a = 19b -6
Only option is 42, which satisfies the equation

Correct Option: 10 Best Solution (11)

ASHOK ROY   14 years AGO

42 IN REVERSE ORDER IS 24 SO 2*24-6=42

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Dr.Dipin Singh   14 years AGO

if x=AB, then 10A+B = 2*(10B+A)-6 or

8*A= 19*B-6 means A=4 and B=2, then X=42

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sanjib biswas   14 years AGO

because 42+6=24*2

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Karthik Pandiyan   14 years AGO

ans:42

x=2y-6
on solving this,we get 42=2(24)-6
42=48-6
42=42

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SUDESHNA SEN   14 years AGO

Let x=10a+b and y= 10b+a.
Then as per the given condition,
x= 2y-6
or, 10a+b= 2(10b+a)-6
or, 10a+b= 20b+2a-6
or, 8a=19b-6
or, a=(19b-6)/8
Now putting b=1,2,3,...,9 we have an integer value for a only when b=2.
Therefore, b=2 and a= (19*2-6)/8= 32/8=4
So, x= 10a+b= 10*4+2= 42.....Option 10)

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Sukham   14 years AGO

42= 2*24-6

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neena   14 years AGO

24*2=48-42=6

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Bimal   14 years AGO

x=2y-6 where x=42 and y =24

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Ankur Pandey   14 years AGO

X=AB;
10*A+B=10B+A-6;
SO,X=42;

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Karan   14 years AGO

Only probable options are 62 and 42. when checked under given conditions, 42 satisfies given condition. so option 10.

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Sahil   14 years AGO

only 42 meets given condition.

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