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A two digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number , the digits are reversed. Find the number?
Verified Answer
A two digit number is 4 more than 6 times the sum of its digits. If 18...
Let x = ones digit
and y = tens digit
then from "a two digit number is 4 more than six times the sum of its digits":
x + 10y = 6(x+y)+4
x + 10y = 6x+6y+4
10y = 5x+6y+4
4y = 5x+4
and, from "if 18 is subtracted from the number, the digits are reversed. find the number"
x+10y -18 = y+10x
10y -18 = y+9x
9y -18 = 9x
y -2 = x
substitute the above into:
4y = 5x+4
4y = 5(y-2)+4
4y = 5y-10+4
4y = 5y-6
4y+6 = 5y
6 = y
substitute above into:
4y = 5x+4
4(6) = 5x+4
24 = 5x+4
20 = 5x
4 = x
The number is 64
This question is part of UPSC exam. View all Class 9 courses
Most Upvoted Answer
A two digit number is 4 more than 6 times the sum of its digits. If 18...
**Problem Statement:**

A two-digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number, the digits are reversed. Find the number?

**Solution:**

Let's assume the two-digit number to be "10x + y", where x and y represent the tens and units digits, respectively.

**Given Information:**

- The two-digit number is 4 more than 6 times the sum of its digits.
- If 18 is subtracted from the number, the digits are reversed.

**Step 1: Express the number in terms of its digits**

Based on the given information, we can express the two-digit number as follows:

"10x + y = 6(x + y) + 4"

**Step 2: Simplify the equation**

Let's simplify the equation obtained in Step 1:

10x + y = 6x + 6y + 4

**Step 3: Rearrange the equation**

To solve for the values of x and y, let's rearrange the equation:

10x - 6x = 6y - y + 4

4x = 5y + 4

**Step 4: Express x in terms of y**

Now, let's express x in terms of y by dividing both sides of the equation by 4:

x = (5y + 4)/4

**Step 5: Substitute the value of x in the equation**

Substitute the value of x from Step 4 into the original equation:

10((5y + 4)/4) + y = 6((5y + 4)/4) + 4

Simplify the equation:

(50y + 40)/4 + y = (30y + 24)/2 + 4

**Step 6: Solve the equation**

To solve the equation, let's multiply both sides by 4 to get rid of the denominators:

50y + 40 + 4y = 60y + 48 + 8

54y + 40 = 60y + 56

Subtract 54y from both sides:

40 = 6y + 56

Subtract 56 from both sides:

-16 = 6y

Divide both sides by 6:

y = -16/6

Simplify:

y = -8/3

But y represents the units digit, which should be a whole number. Since -8/3 is not a whole number, there is no solution to this equation.

Therefore, there is no two-digit number that satisfies the given conditions.
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A two digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number , the digits are reversed. Find the number?
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A two digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number , the digits are reversed. Find the number? for Class 9 2024 is part of Class 9 preparation. The Question and answers have been prepared according to the Class 9 exam syllabus. Information about A two digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number , the digits are reversed. Find the number? covers all topics & solutions for Class 9 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A two digit number is 4 more than 6 times the sum of its digits. If 18 is subtracted from the number , the digits are reversed. Find the number?.
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