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Question : 29 of 39

Marks: +1, -0

A number consist of three digit of which the middle one is zero and the sum of other digits is

9 .

The number formed by interchanging the first and third digits is more than the original number by 297 find the number?

306
309
603
307

Solution:

Concept:

Let the hundreds digit be

a

and units digit be

c

. The number is

100a + c

, with

a + c = 9

.

Explanation:

After interchanging, the new number is

100c + a

.

The difference is

(100c + a) - (100a + c) = 99(c - a) = 297

.

So

c - a = 3

.

Solve

a + c = 9

and

c - a = 3

: adding gives

2c = 12 \Rightarrow c = 6

, then

a = 3

.

Thus the number is

306

.

Answer:

The number is

306

.

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