What is 9/33 plus 10/21? (Answer: 173/231)

Exact Answer

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Problem: What is 9/33 plus 10/21?
Formula / Expression: 9/33 + 10/21
Final Answer: 173/231
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 33 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 231 (which is smaller than their product 33 × 21 = 693, keeping the calculation simpler).
Working: LCD(33, 21) = 231

Step 2: Convert to Equivalent Fractions with Common Denominator 231
Multiply the numerator and denominator of 9/33 by 7, and multiply the numerator and denominator of 10/21 by 11 so both fractions share the common base 231.
Working: 9 × 7/33 × 7 = 63/231 and 10 × 11/21 × 11 = 110/231

Step 3: Add the Numerators
Now add the numerators (63 + 110 = 173) and keep the common denominator 231 unchanged.
Working: 63 + 110/231 = 173/231

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 173 and 231 is 1, confirming that 173/231 cannot be reduced further—it is already in its simplest irreducible form.
Working: 173/231

Step 5: Decimal & Percentage Representation
Dividing the numerator 173 by denominator 231 produces a repeating decimal (approximately 0.748918, or 74.8918%).
Working: 173 ÷ 231 = 0.748918 (74.8918%)

Key Values:
- Simplified Fraction: 173/231
- Mixed Number Form: 173/231
- Decimal Value: 0.748918
- Percentage: 74.8918%

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Solved with FractionsCalc:
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9/33 + 10/21 = 173/231

Simplified Fraction

173/231

Mixed Number

Proper (173/231)

Decimal Value

0.748918

Percentage

74.8918%

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Step-by-Step Solution: 9/33 + 10/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 33 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 231 (which is smaller than their product 33 × 21 = 693, keeping the calculation simpler).

LCD(33, 21) = 231

Step 2

Convert to Equivalent Fractions with Common Denominator 231

Multiply the numerator and denominator of 9/33 by 7, and multiply the numerator and denominator of 10/21 by 11 so both fractions share the common base 231.

9 × 7/33 × 7 = 63/231 and 10 × 11/21 × 11 = 110/231

Step 3

Add the Numerators

Now add the numerators (63 + 110 = 173) and keep the common denominator 231 unchanged.

63 + 110/231 = 173/231

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 173 and 231 is 1, confirming that 173/231 cannot be reduced further—it is already in its simplest irreducible form.

173/231

Step 5

Decimal & Percentage Representation

Dividing the numerator 173 by denominator 231 produces a repeating decimal (approximately 0.748918, or 74.8918%).

173 ÷ 231 = 0.748918 (74.8918%)

Visual Representation

The diagram below illustrates 9/33 plus 10/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`173/231`
Mixed Number Form	`173/231`
Decimal Form	`0.748918`
Percentage	`74.8918%`

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Frequently Asked Questions

What is 9/33 plus 10/21 as a fraction?

9/33 + 10/21 in simplest fraction form is 173/231.

What is 9/33 plus 10/21 as a decimal?

9/33 + 10/21 converted to a decimal is 0.748918.

What is 9/33 plus 10/21 as a percentage?

9/33 + 10/21 expressed as a percentage is 74.8918%.

Does 9/33 plus 10/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.748918...) because the denominator contains prime factors other than 2 and 5.