What is 12/60 plus 7/21? (Answer: 8/15)

Exact Answer

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Problem: What is 12/60 plus 7/21?
Formula / Expression: 12/60 + 7/21
Final Answer: 8/15
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 60 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 420 (which is smaller than their product 60 × 21 = 1260, keeping the calculation simpler).
Working: LCD(60, 21) = 420

Step 2: Convert to Equivalent Fractions with Common Denominator 420
Multiply the numerator and denominator of 12/60 by 7, and multiply the numerator and denominator of 7/21 by 20 so both fractions share the common base 420.
Working: 12 × 7/60 × 7 = 84/420 and 7 × 20/21 × 20 = 140/420

Step 3: Add the Numerators
Now add the numerators (84 + 140 = 224) and keep the common denominator 420 unchanged.
Working: 84 + 140/420 = 224/420

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 224 and 420, which is 28. Divide both the numerator and denominator by 28.
Working: 224 ÷ 28/420 ÷ 28 = 8/15

Step 5: Decimal & Percentage Representation
Dividing the numerator 8 by denominator 15 produces a repeating decimal (approximately 0.533333, or 53.3333%).
Working: 8 ÷ 15 = 0.533333 (53.3333%)

Key Values:
- Simplified Fraction: 8/15
- Mixed Number Form: 8/15
- Decimal Value: 0.533333
- Percentage: 53.3333%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-12-60-plus-7-21/
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12/60 + 7/21 = 8/15

Simplified Fraction

8/15

Mixed Number

Proper (8/15)

Decimal Value

0.533333

Percentage

53.3333%

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Step-by-Step Solution: 12/60 + 7/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 60 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 420 (which is smaller than their product 60 × 21 = 1260, keeping the calculation simpler).

LCD(60, 21) = 420

Step 2

Convert to Equivalent Fractions with Common Denominator 420

Multiply the numerator and denominator of 12/60 by 7, and multiply the numerator and denominator of 7/21 by 20 so both fractions share the common base 420.

12 × 7/60 × 7 = 84/420 and 7 × 20/21 × 20 = 140/420

Step 3

Add the Numerators

Now add the numerators (84 + 140 = 224) and keep the common denominator 420 unchanged.

84 + 140/420 = 224/420

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 224 and 420, which is 28. Divide both the numerator and denominator by 28.

224 ÷ 28/420 ÷ 28 = 8/15

Step 5

Decimal & Percentage Representation

Dividing the numerator 8 by denominator 15 produces a repeating decimal (approximately 0.533333, or 53.3333%).

8 ÷ 15 = 0.533333 (53.3333%)

Visual Representation

The diagram below illustrates 12/60 plus 7/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`8/15`
Mixed Number Form	`8/15`
Decimal Form	`0.533333`
Percentage	`53.3333%`

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Frequently Asked Questions

What is 12/60 plus 7/21 as a fraction?

12/60 + 7/21 in simplest fraction form is 8/15.

What is 12/60 plus 7/21 as a decimal?

12/60 + 7/21 converted to a decimal is 0.533333.

What is 12/60 plus 7/21 as a percentage?

12/60 + 7/21 expressed as a percentage is 53.3333%.

Does 12/60 plus 7/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.533333...) because the denominator contains prime factors other than 2 and 5.