What is 15/29 plus 11/21? (Answer: 634/609)

Exact Answer

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Problem: What is 15/29 plus 11/21?
Formula / Expression: 15/29 + 11/21
Final Answer: 1 25/609 (634/609)
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 29 and 21 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 29 × 21 = 609.
Working: LCD(29, 21) = 609

Step 2: Convert to Equivalent Fractions with Common Denominator 609
Multiply the numerator and denominator of 15/29 by 21, and multiply the numerator and denominator of 11/21 by 29 so both fractions share the common base 609.
Working: 15 × 21/29 × 21 = 315/609 and 11 × 29/21 × 29 = 319/609

Step 3: Add the Numerators
Now add the numerators (315 + 319 = 634) and keep the common denominator 609 unchanged.
Working: 315 + 319/609 = 634/609

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 634 and 609 is 1, confirming that 634/609 cannot be reduced further—it is already in its simplest irreducible form.
Working: 634/609

Step 5: Convert Improper Fraction to a Mixed Number
Since the numerator (634) is greater than the denominator (609), divide 634 by 609: it goes in 1 whole time(s) with a remainder of 25, giving the mixed number 1 25/609.
Working: 634/609 = 1 25/609

Step 6: Decimal & Percentage Representation
Dividing the numerator 634 by denominator 609 produces a repeating decimal (approximately 1.041051, or 104.1051%).
Working: 634 ÷ 609 = 1.041051 (104.1051%)

Key Values:
- Simplified Fraction: 634/609
- Mixed Number Form: 1 25/609
- Decimal Value: 1.041051
- Percentage: 104.1051%

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15/29 + 11/21 = 634/609

Simplified Fraction

634/609

Mixed Number

1 25/609

Decimal Value

1.041051

Percentage

104.1051%

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Step-by-Step Solution: 15/29 + 11/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 29 and 21 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 29 × 21 = 609.

LCD(29, 21) = 609

Step 2

Convert to Equivalent Fractions with Common Denominator 609

Multiply the numerator and denominator of 15/29 by 21, and multiply the numerator and denominator of 11/21 by 29 so both fractions share the common base 609.

15 × 21/29 × 21 = 315/609 and 11 × 29/21 × 29 = 319/609

Step 3

Add the Numerators

Now add the numerators (315 + 319 = 634) and keep the common denominator 609 unchanged.

315 + 319/609 = 634/609

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 634 and 609 is 1, confirming that 634/609 cannot be reduced further—it is already in its simplest irreducible form.

634/609

Step 5

Convert Improper Fraction to a Mixed Number

Since the numerator (634) is greater than the denominator (609), divide 634 by 609: it goes in 1 whole time(s) with a remainder of 25, giving the mixed number 1 25/609.

634/609 = 125/609

Step 6

Decimal & Percentage Representation

Dividing the numerator 634 by denominator 609 produces a repeating decimal (approximately 1.041051, or 104.1051%).

634 ÷ 609 = 1.041051 (104.1051%)

Visual Representation

The diagram below illustrates 15/29 plus 11/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`634/609`
Mixed Number Form	`1 25/609`
Decimal Form	`1.041051`
Percentage	`104.1051%`

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Frequently Asked Questions

What is 15/29 plus 11/21 as a fraction?

15/29 + 11/21 in simplest fraction form is 634/609 (or 1 25/609 as a mixed number).

What is 15/29 plus 11/21 as a decimal?

15/29 + 11/21 converted to a decimal is 1.041051.

What is 15/29 plus 11/21 as a percentage?

15/29 + 11/21 expressed as a percentage is 104.1051%.

How do you write 15/29 plus 11/21 as a mixed number?

Because the numerator is greater than the denominator, the improper fraction 634/609 can be written as the mixed number 1 25/609.

Does 15/29 plus 11/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 1.041051...) because the denominator contains prime factors other than 2 and 5.