Let be a natural number such that . If its left-most digit is deleted, it gets reduced to .
Find .
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Let N = abcd, where a,b,c,d are single digit whole numbers, and a>0.
So, we may write, N= 1 0 3 a + 1 0 2 b + 1 0 c + d .
Therefore, 2 9 N = 1 0 2 b + 1 0 c + d .
Now, from the two equations, we get, 1 0 3 a = 2 8 ( 1 0 2 b + 1 0 c + d ) So, 2 8 = 7 ∗ 2 2 is a factor of 1 0 3 a , which means that 1 0 3 a must contain a power of 7 in its prime factorisation.
So, a has to be one among 7 , 1 4 , 2 1 , . . . . But, a is a one-digit number, so only possible value of a is 7 . After, putting a = 7 in the third equation, we get
1 0 0 b + 1 0 c + d = 2 5 0 .
Each of b,c and d is a one-digit number, so, their values are:
b = 2 , c = 5 , d = 0 .
Hence, N is 7 2 5 0 .