What is 16/45 plus 9/21? (Answer: 247/315)

Exact Answer

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Problem: What is 16/45 plus 9/21?
Formula / Expression: 16/45 + 9/21
Final Answer: 247/315
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 45 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 315 (which is smaller than their product 45 × 21 = 945, keeping the calculation simpler).
Working: LCD(45, 21) = 315

Step 2: Convert to Equivalent Fractions with Common Denominator 315
Multiply the numerator and denominator of 16/45 by 7, and multiply the numerator and denominator of 9/21 by 15 so both fractions share the common base 315.
Working: 16 × 7/45 × 7 = 112/315 and 9 × 15/21 × 15 = 135/315

Step 3: Add the Numerators
Now add the numerators (112 + 135 = 247) and keep the common denominator 315 unchanged.
Working: 112 + 135/315 = 247/315

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 247 and 315 is 1, confirming that 247/315 cannot be reduced further—it is already in its simplest irreducible form.
Working: 247/315

Step 5: Decimal & Percentage Representation
Dividing the numerator 247 by denominator 315 produces a repeating decimal (approximately 0.784127, or 78.4127%).
Working: 247 ÷ 315 = 0.784127 (78.4127%)

Key Values:
- Simplified Fraction: 247/315
- Mixed Number Form: 247/315
- Decimal Value: 0.784127
- Percentage: 78.4127%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-16-45-plus-9-21/
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16/45 + 9/21 = 247/315

Simplified Fraction

247/315

Mixed Number

Proper (247/315)

Decimal Value

0.784127

Percentage

78.4127%

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Step-by-Step Solution: 16/45 + 9/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 45 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 315 (which is smaller than their product 45 × 21 = 945, keeping the calculation simpler).

LCD(45, 21) = 315

Step 2

Convert to Equivalent Fractions with Common Denominator 315

Multiply the numerator and denominator of 16/45 by 7, and multiply the numerator and denominator of 9/21 by 15 so both fractions share the common base 315.

16 × 7/45 × 7 = 112/315 and 9 × 15/21 × 15 = 135/315

Step 3

Add the Numerators

Now add the numerators (112 + 135 = 247) and keep the common denominator 315 unchanged.

112 + 135/315 = 247/315

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 247 and 315 is 1, confirming that 247/315 cannot be reduced further—it is already in its simplest irreducible form.

247/315

Step 5

Decimal & Percentage Representation

Dividing the numerator 247 by denominator 315 produces a repeating decimal (approximately 0.784127, or 78.4127%).

247 ÷ 315 = 0.784127 (78.4127%)

Visual Representation

The diagram below illustrates 16/45 plus 9/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`247/315`
Mixed Number Form	`247/315`
Decimal Form	`0.784127`
Percentage	`78.4127%`

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Frequently Asked Questions

What is 16/45 plus 9/21 as a fraction?

16/45 + 9/21 in simplest fraction form is 247/315.

What is 16/45 plus 9/21 as a decimal?

16/45 + 9/21 converted to a decimal is 0.784127.

What is 16/45 plus 9/21 as a percentage?

16/45 + 9/21 expressed as a percentage is 78.4127%.

Does 16/45 plus 9/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.784127...) because the denominator contains prime factors other than 2 and 5.