What is 9/35 plus 10/21? (Answer: 11/15)

Exact Answer

==================================================
Problem: What is 9/35 plus 10/21?
Formula / Expression: 9/35 + 10/21
Final Answer: 11/15
==================================================

Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 35 and 21 share a common factor (GCD = 7). Finding their Least Common Multiple gives an LCD of 105 (which is smaller than their product 35 × 21 = 735, keeping the calculation simpler).
Working: LCD(35, 21) = 105

Step 2: Convert to Equivalent Fractions with Common Denominator 105
Multiply the numerator and denominator of 9/35 by 3, and multiply the numerator and denominator of 10/21 by 5 so both fractions share the common base 105.
Working: 9 × 3/35 × 3 = 27/105 and 10 × 5/21 × 5 = 50/105

Step 3: Add the Numerators
Now add the numerators (27 + 50 = 77) and keep the common denominator 105 unchanged.
Working: 27 + 50/105 = 77/105

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 77 and 105, which is 7. Divide both the numerator and denominator by 7.
Working: 77 ÷ 7/105 ÷ 7 = 11/15

Step 5: Decimal & Percentage Representation
Dividing the numerator 11 by denominator 15 produces a repeating decimal (approximately 0.733333, or 73.3333%).
Working: 11 ÷ 15 = 0.733333 (73.3333%)

Key Values:
- Simplified Fraction: 11/15
- Mixed Number Form: 11/15
- Decimal Value: 0.733333
- Percentage: 73.3333%

--------------------------------------------------
Solved with FractionsCalc:
https://fractionscalc.com/what-is-9-35-plus-10-21/
==================================================

9/35 + 10/21 = 11/15

Simplified Fraction

11/15

Mixed Number

Proper (11/15)

Decimal Value

0.733333

Percentage

73.3333%

Reduce / Convert Fraction:

Convert Fraction:

Enter Decimal Number:

Enter Percentage: %

What is % of

From Value: To Value:

Simplify Ratio: :

Switch to Proportion / Missing X Solver (A/B = C/D) →

Enter 3 known numbers and leave 1 empty (or type x) to solve:

← Switch to Ratio Simplifier (A:B)

Provide any 2 values below to calculate the remaining:

Price before discount

Discount

Price after discount

You saved

+ Add Sales Tax & Extra Coupon (Optional)

Sales Tax: % Extra Off: %

Provide any 2 values below to calculate the remaining:

Cost

Markup

REVENUE

Gross Profit

Profit Margin

Bill Subtotal

Tip Percentage

Split (People)

👥

Quick Tip:

Total Bill

Split Between

👥

Tip % (Optional)

Include Tip:

Total Price

Quantity

Unit of Measure

← Discount & Sales Tax • Ratio Simplifier (A:B) →

First Number: Second Number:

Find All Factors of:

Dividend: ÷ Divisor:

Number to Round: To Nearest:

Method: Standard (5+ ↑) Always Up (Ceil) Always Down (Floor)

Presets:

√ Square Root of: OR Power (x^y): ^{^}

x² + x + = 0

Number (n! & log):

Circle Radius (r):

Side a: Side b:

Angle (Degrees): °

Numbers (comma separated):

Total Items (n): Choose (r):

Decimal Number:

Number (1–3999):

Step-by-Step Solution: 9/35 + 10/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 35 and 21 share a common factor (GCD = 7). Finding their Least Common Multiple gives an LCD of 105 (which is smaller than their product 35 × 21 = 735, keeping the calculation simpler).

LCD(35, 21) = 105

Step 2

Convert to Equivalent Fractions with Common Denominator 105

Multiply the numerator and denominator of 9/35 by 3, and multiply the numerator and denominator of 10/21 by 5 so both fractions share the common base 105.

9 × 3/35 × 3 = 27/105 and 10 × 5/21 × 5 = 50/105

Step 3

Add the Numerators

Now add the numerators (27 + 50 = 77) and keep the common denominator 105 unchanged.

27 + 50/105 = 77/105

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 77 and 105, which is 7. Divide both the numerator and denominator by 7.

77 ÷ 7/105 ÷ 7 = 11/15

Step 5

Decimal & Percentage Representation

Dividing the numerator 11 by denominator 15 produces a repeating decimal (approximately 0.733333, or 73.3333%).

11 ÷ 15 = 0.733333 (73.3333%)

Visual Representation

The diagram below illustrates 9/35 plus 10/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`11/15`
Mixed Number Form	`11/15`
Decimal Form	`0.733333`
Percentage	`73.3333%`

Was this solution helpful?

Help us improve our free step-by-step tools

Frequently Asked Questions

What is 9/35 plus 10/21 as a fraction?

9/35 + 10/21 in simplest fraction form is 11/15.

What is 9/35 plus 10/21 as a decimal?

9/35 + 10/21 converted to a decimal is 0.733333.

What is 9/35 plus 10/21 as a percentage?

9/35 + 10/21 expressed as a percentage is 73.3333%.

Does 9/35 plus 10/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.733333...) because the denominator contains prime factors other than 2 and 5.