What is 19/27 plus 15/21?
19/27 plus 15/21 equals 268/189 (or 1 79/189 as a mixed number) (or 1.417989 in decimal form). Learn the step-by-step solution to add 19/27 and 15/21 using Least Common Denominator and simplification.
Exact Answer
19/27 + 15/21 = 268/189
Simplified Fraction
268/189
Mixed Number
1 79/189
Decimal Value
1.417989
Percentage
141.7989%
Step-by-Step Solution: 19/27 + 15/21
Step 1
Find the Least Common Denominator (LCD)
The denominators 27 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 189 (which is smaller than their product 27 × 21 = 567, keeping the calculation simpler).
LCD(27, 21) = 189
Step 2
Convert to Equivalent Fractions with Common Denominator 189
Multiply the numerator and denominator of 19/27 by 7, and multiply the numerator and denominator of 15/21 by 9 so both fractions share the common base 189.
19 × 7/27 × 7 = 133/189 and 15 × 9/21 × 9 = 135/189
Step 3
Add the Numerators
Now add the numerators (133 + 135 = 268) and keep the common denominator 189 unchanged.
133 + 135/189 = 268/189
Step 4
Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 268 and 189 is 1, confirming that 268/189 cannot be reduced further—it is already in its simplest irreducible form.
268/189
Step 5
Convert Improper Fraction to a Mixed Number
Since the numerator (268) is greater than the denominator (189), divide 268 by 189: it goes in 1 whole time(s) with a remainder of 79, giving the mixed number 1 79/189.
268/189 = 179/189
Step 6
Decimal & Percentage Representation
Dividing the numerator 268 by denominator 189 produces a repeating decimal (approximately 1.417989, or 141.7989%).
268 ÷ 189 = 1.417989 (141.7989%)
Visual Representation
The diagram below illustrates 19/27 plus 15/21 visually:
+
=
Summary & Alternative Representations
| Property / Format | Value |
|---|---|
| Lowest Terms Fraction | 268/189 |
| Mixed Number Form | 1 79/189 |
| Decimal Form | 1.417989 |
| Percentage | 141.7989% |
Was this solution helpful?
Help us improve our free step-by-step tools
Frequently Asked Questions
What is 19/27 plus 15/21 as a fraction?
19/27 + 15/21 in simplest fraction form is 268/189 (or 1 79/189 as a mixed number).
What is 19/27 plus 15/21 as a decimal?
19/27 + 15/21 converted to a decimal is 1.417989.
What is 19/27 plus 15/21 as a percentage?
19/27 + 15/21 expressed as a percentage is 141.7989%.
How do you write 19/27 plus 15/21 as a mixed number?
Because the numerator is greater than the denominator, the improper fraction 268/189 can be written as the mixed number 1 79/189.
Does 19/27 plus 15/21 result in a terminating or repeating decimal?
It results in a repeating decimal (approximately 1.417989...) because the denominator contains prime factors other than 2 and 5.