Question

Find all numbers such that the difference between 13 and twice the number is less than -15

Answer 1

Answer:

two digit number has two places, a unit digit, and a tens digit.

Let the tens digit be X/10. So without the unit digit, the number would be (X/10) * 10 = X.

let the unit digit be Y.

So the original number is : X + Y ………………………………….. (1)

I will explain this a little more. take a two digit number. for e.g. 27.

Nox X/10 is 2 and X is 20. Y is 7.

So X + Y = 20 + 7 = 27

Now, if you want to interchange the digits, the X will be at the units place and the Y will be at tens place.

So we will write it as : (Y * 10) + (X / 10)………………………….(2)

Now (Y * 10) + (X / 10) = (7 * 10) + (20 / 10) = 70 + 2 = 72.

Now, in your question, you said that the difference between the a digit number(i.e. X + Y) and the number formed by interchanging the digits(i.e. (Y * 10) + (X / 10)) is 63.

So therefore,

[X + Y] - [(Y * 10) + (X / 10)] = 63………………………………….(3)

[X - (X / 10)] + [Y - (Y * 10)] = 63

[9X / 10] + [9Y / 10] = 63

[9 * (X + Y)] / 10 = 63.

9 * (X + Y) = 63 * 10 = 630

X + Y = 630 / 9

X + Y = 70.

If you write it as:

X + Y = 70 + 0

X = 70, Y = 0

Now Substitute the same into third equation

[70 + 0] - [(0 * 10) + (70 / 10)] = 63

70 - [0 + 7] = 63

70 - 7 = 63

63 = 63.

So X and Y are verified.

Now answering your main question:

difference between the digits of the number = (X/10) - Y = (70/10) - 0 = 7 - 0 = 7.

So 7 is the answer

The difference of 2 digit number & the number obtained by interchanging the digits is 36. What is the difference the sum and the number if the ratio between the digits of the number is 1:2 ?

The difference between a two digit number that’s obtained by interchanging the position of its digits is 36. What is the difference between the two digits of that number?

The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 72. What is the difference between the two digits of that number?

The difference of 2-digit number and the number obtained by reversing the digit is 27,find the difference between the digits of the 2-digit number?

The difference between a two-digit number and the number obtained by interchanging the two digits is 63. Which is the smaller of the two numbers?

Two digit number has a ten’s digit and one’s digit.

Let x be the ten’s digit and y be the one’s digit. Then,

The number = 10x+y

The number formed by interchanging its digits = 10y+x

The difference between them is 63.

i.e (10x+y)-(10y+x) =63

9x-9y =63

x-y =7

Ans: The difference between the digits of the number 7

Note:

If ‘d’ is the difference of a number and the one formed by reversing its digits, it will be a multiple of 9.

Then the difference between the digits = d/9

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