What is 1/30 plus 12/21? (Answer: 127/210)

Exact Answer

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Problem: What is 1/30 plus 12/21?
Formula / Expression: 1/30 + 12/21
Final Answer: 127/210
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 30 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 210 (which is smaller than their product 30 × 21 = 630, keeping the calculation simpler).
Working: LCD(30, 21) = 210

Step 2: Convert to Equivalent Fractions with Common Denominator 210
Multiply the numerator and denominator of 1/30 by 7, and multiply the numerator and denominator of 12/21 by 10 so both fractions share the common base 210.
Working: 1 × 7/30 × 7 = 7/210 and 12 × 10/21 × 10 = 120/210

Step 3: Add the Numerators
Now add the numerators (7 + 120 = 127) and keep the common denominator 210 unchanged.
Working: 7 + 120/210 = 127/210

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 127 and 210 is 1, confirming that 127/210 cannot be reduced further—it is already in its simplest irreducible form.
Working: 127/210

Step 5: Decimal & Percentage Representation
Dividing the numerator 127 by denominator 210 produces a repeating decimal (approximately 0.604762, or 60.4762%).
Working: 127 ÷ 210 = 0.604762 (60.4762%)

Key Values:
- Simplified Fraction: 127/210
- Mixed Number Form: 127/210
- Decimal Value: 0.604762
- Percentage: 60.4762%

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Solved with FractionsCalc:
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1/30 + 12/21 = 127/210

Simplified Fraction

127/210

Mixed Number

Proper (127/210)

Decimal Value

0.604762

Percentage

60.4762%

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Step-by-Step Solution: 1/30 + 12/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 30 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 210 (which is smaller than their product 30 × 21 = 630, keeping the calculation simpler).

LCD(30, 21) = 210

Step 2

Convert to Equivalent Fractions with Common Denominator 210

Multiply the numerator and denominator of 1/30 by 7, and multiply the numerator and denominator of 12/21 by 10 so both fractions share the common base 210.

1 × 7/30 × 7 = 7/210 and 12 × 10/21 × 10 = 120/210

Step 3

Add the Numerators

Now add the numerators (7 + 120 = 127) and keep the common denominator 210 unchanged.

7 + 120/210 = 127/210

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 127 and 210 is 1, confirming that 127/210 cannot be reduced further—it is already in its simplest irreducible form.

127/210

Step 5

Decimal & Percentage Representation

Dividing the numerator 127 by denominator 210 produces a repeating decimal (approximately 0.604762, or 60.4762%).

127 ÷ 210 = 0.604762 (60.4762%)

Visual Representation

The diagram below illustrates 1/30 plus 12/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`127/210`
Mixed Number Form	`127/210`
Decimal Form	`0.604762`
Percentage	`60.4762%`

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Frequently Asked Questions

What is 1/30 plus 12/21 as a fraction?

1/30 + 12/21 in simplest fraction form is 127/210.

What is 1/30 plus 12/21 as a decimal?

1/30 + 12/21 converted to a decimal is 0.604762.

What is 1/30 plus 12/21 as a percentage?

1/30 + 12/21 expressed as a percentage is 60.4762%.

Does 1/30 plus 12/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.604762...) because the denominator contains prime factors other than 2 and 5.