What is 13/52 plus 9/21? (Answer: 19/28)

Exact Answer

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Problem: What is 13/52 plus 9/21?
Formula / Expression: 13/52 + 9/21
Final Answer: 19/28
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 52 and 21 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 52 × 21 = 1092.
Working: LCD(52, 21) = 1092

Step 2: Convert to Equivalent Fractions with Common Denominator 1092
Multiply the numerator and denominator of 13/52 by 21, and multiply the numerator and denominator of 9/21 by 52 so both fractions share the common base 1092.
Working: 13 × 21/52 × 21 = 273/1092 and 9 × 52/21 × 52 = 468/1092

Step 3: Add the Numerators
Now add the numerators (273 + 468 = 741) and keep the common denominator 1092 unchanged.
Working: 273 + 468/1092 = 741/1092

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 741 and 1092, which is 39. Divide both the numerator and denominator by 39.
Working: 741 ÷ 39/1092 ÷ 39 = 19/28

Step 5: Decimal & Percentage Representation
Dividing the numerator 19 by denominator 28 produces a repeating decimal (approximately 0.678571, or 67.8571%).
Working: 19 ÷ 28 = 0.678571 (67.8571%)

Key Values:
- Simplified Fraction: 19/28
- Mixed Number Form: 19/28
- Decimal Value: 0.678571
- Percentage: 67.8571%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-13-52-plus-9-21/
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13/52 + 9/21 = 19/28

Simplified Fraction

19/28

Mixed Number

Proper (19/28)

Decimal Value

0.678571

Percentage

67.8571%

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Step-by-Step Solution: 13/52 + 9/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 52 and 21 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 52 × 21 = 1092.

LCD(52, 21) = 1092

Step 2

Convert to Equivalent Fractions with Common Denominator 1092

Multiply the numerator and denominator of 13/52 by 21, and multiply the numerator and denominator of 9/21 by 52 so both fractions share the common base 1092.

13 × 21/52 × 21 = 273/1092 and 9 × 52/21 × 52 = 468/1092

Step 3

Add the Numerators

Now add the numerators (273 + 468 = 741) and keep the common denominator 1092 unchanged.

273 + 468/1092 = 741/1092

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 741 and 1092, which is 39. Divide both the numerator and denominator by 39.

741 ÷ 39/1092 ÷ 39 = 19/28

Step 5

Decimal & Percentage Representation

Dividing the numerator 19 by denominator 28 produces a repeating decimal (approximately 0.678571, or 67.8571%).

19 ÷ 28 = 0.678571 (67.8571%)

Visual Representation

The diagram below illustrates 13/52 plus 9/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`19/28`
Mixed Number Form	`19/28`
Decimal Form	`0.678571`
Percentage	`67.8571%`

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Frequently Asked Questions

What is 13/52 plus 9/21 as a fraction?

13/52 + 9/21 in simplest fraction form is 19/28.

What is 13/52 plus 9/21 as a decimal?

13/52 + 9/21 converted to a decimal is 0.678571.

What is 13/52 plus 9/21 as a percentage?

13/52 + 9/21 expressed as a percentage is 67.8571%.

Does 13/52 plus 9/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.678571...) because the denominator contains prime factors other than 2 and 5.