What is 11/28 plus 9/13? (Answer: 395/364)

Exact Answer

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Problem: What is 11/28 plus 9/13?
Formula / Expression: 11/28 + 9/13
Final Answer: 1 31/364 (395/364)
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 28 and 13 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 28 × 13 = 364.
Working: LCD(28, 13) = 364

Step 2: Convert to Equivalent Fractions with Common Denominator 364
Multiply the numerator and denominator of 11/28 by 13, and multiply the numerator and denominator of 9/13 by 28 so both fractions share the common base 364.
Working: 11 × 13/28 × 13 = 143/364 and 9 × 28/13 × 28 = 252/364

Step 3: Add the Numerators
Now add the numerators (143 + 252 = 395) and keep the common denominator 364 unchanged.
Working: 143 + 252/364 = 395/364

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 395 and 364 is 1, confirming that 395/364 cannot be reduced further—it is already in its simplest irreducible form.
Working: 395/364

Step 5: Convert Improper Fraction to a Mixed Number
Since the numerator (395) is greater than the denominator (364), divide 395 by 364: it goes in 1 whole time(s) with a remainder of 31, giving the mixed number 1 31/364.
Working: 395/364 = 1 31/364

Step 6: Decimal & Percentage Representation
Dividing the numerator 395 by denominator 364 produces a repeating decimal (approximately 1.085165, or 108.5165%).
Working: 395 ÷ 364 = 1.085165 (108.5165%)

Key Values:
- Simplified Fraction: 395/364
- Mixed Number Form: 1 31/364
- Decimal Value: 1.085165
- Percentage: 108.5165%

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Solved with FractionsCalc:
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11/28 + 9/13 = 395/364

Simplified Fraction

395/364

Mixed Number

1 31/364

Decimal Value

1.085165

Percentage

108.5165%

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Step-by-Step Solution: 11/28 + 9/13

Step 1

Find the Least Common Denominator (LCD)

The denominators 28 and 13 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 28 × 13 = 364.

LCD(28, 13) = 364

Step 2

Convert to Equivalent Fractions with Common Denominator 364

Multiply the numerator and denominator of 11/28 by 13, and multiply the numerator and denominator of 9/13 by 28 so both fractions share the common base 364.

11 × 13/28 × 13 = 143/364 and 9 × 28/13 × 28 = 252/364

Step 3

Add the Numerators

Now add the numerators (143 + 252 = 395) and keep the common denominator 364 unchanged.

143 + 252/364 = 395/364

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 395 and 364 is 1, confirming that 395/364 cannot be reduced further—it is already in its simplest irreducible form.

395/364

Step 5

Convert Improper Fraction to a Mixed Number

Since the numerator (395) is greater than the denominator (364), divide 395 by 364: it goes in 1 whole time(s) with a remainder of 31, giving the mixed number 1 31/364.

395/364 = 131/364

Step 6

Decimal & Percentage Representation

Dividing the numerator 395 by denominator 364 produces a repeating decimal (approximately 1.085165, or 108.5165%).

395 ÷ 364 = 1.085165 (108.5165%)

Visual Representation

The diagram below illustrates 11/28 plus 9/13 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`395/364`
Mixed Number Form	`1 31/364`
Decimal Form	`1.085165`
Percentage	`108.5165%`

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Frequently Asked Questions

What is 11/28 plus 9/13 as a fraction?

11/28 + 9/13 in simplest fraction form is 395/364 (or 1 31/364 as a mixed number).

What is 11/28 plus 9/13 as a decimal?

11/28 + 9/13 converted to a decimal is 1.085165.

What is 11/28 plus 9/13 as a percentage?

11/28 + 9/13 expressed as a percentage is 108.5165%.

How do you write 11/28 plus 9/13 as a mixed number?

Because the numerator is greater than the denominator, the improper fraction 395/364 can be written as the mixed number 1 31/364.

Does 11/28 plus 9/13 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 1.085165...) because the denominator contains prime factors other than 2 and 5.