Addition or Subtraction of Unit Fractions Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Addition or Subtraction of Unit Fractions. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Answer : D

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD is 4 × 7 = 28.

Step 2:

Rewriting as equivalent fractions

$\frac{7}{28}$ + $\frac{4}{28}$ = $\frac{(7+4)}{28}$ = $\frac{11}{28}$

Step 3:

So, $\frac{1}{4}$ + $\frac{1}{7}$ = $\frac{11}{28}$

Q 2 - Subtract $\frac{1}{7}$ − $\frac{1}{10}$

Answer : A

Explanation

Step 1:

Since denominators are same, subtracting the numerators

Here the fractions have unlike denominators. So we find LCD.

LCD = 7 × 10 = 70.

Step 2:

Rewriting as equivalent fractions

$\frac{10}{70}$ − $\frac{7}{70}$ = $\frac{(10-7)}{70}$ = $\frac{3}{70}$

Step 3:

So, $\frac{1}{7}$ − $\frac{1}{10}$ = $\frac{3}{70}$

Answer : C

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD = 2 × 9 = 18.

Step 2:

Rewriting as equivalent fractions

$\frac{9}{18}$ + $\frac{2}{18}$ = $\frac{(9+2)}{18}$ = $\frac{11}{18}$

Step 3:

So, $\frac{1}{2}$ + $\frac{1}{9}$ = $\frac{11}{18}$

Q 4 - Subtract $\frac{1}{9}$ − $\frac{1}{10}$

Answer : B

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD = 9 × 10 = 90.

Step 2:

Rewriting as equivalent fractions

$\frac{10}{90}$ − $\frac{9}{90}$ = $\frac{(10-9)}{90}$ = $\frac{1}{90}$

Step 3:

So, $\frac{1}{9}$ − $\frac{1}{10}$ = $\frac{1}{90}$

Answer : A

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD is 3 × 7 = 21.

Step 2:

Rewriting as equivalent fractions

$\frac{7}{21}$ + $\frac{3}{21}$ = $\frac{(7+3)}{21}$ = $\frac{10}{21}$

Step 3:

So, $\frac{1}{3}$ + $\frac{1}{7}$ = $\frac{10}{21}$

Q 6 - Subtract $\frac{1}{9}$ - $\frac{1}{11}$

Answer : C

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD is 9 × 11 = 99.

Step 2:

Rewriting as equivalent fractions

$\frac{11}{99}$ − $\frac{9}{99}$ = $\frac{(11-9)}{99}$ = $\frac{2}{99}$

Step 3:

So, $\frac{1}{9}$ - $\frac{1}{11}$ = $\frac{2}{99}$

Answer : D

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD of 3 and 6 is 6.

Step 2:

Rewriting as equivalent fractions

$\frac{2}{6}$ + $\frac{1}{6}$ = $\frac{(2+1)}{6}$ = $\frac{3}{6}$ = $\frac{1}{2}$

Step 3:

So, $\frac{1}{3}$ + $\frac{1}{6}$ = $\frac{1}{2}$

Q 8 - Subtract $\frac{1}{6}$ − $\frac{1}{8}$

Answer : B

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD of 6 and 8 = 24.

Step 2:

Rewriting as equivalent fractions

$\frac{4}{24}$ − $\frac{3}{24}$ = $\frac{(4-3)}{24}$ = $\frac{1}{24}$

Step 3:

So, $\frac{1}{6}$ − $\frac{1}{8}$ = $\frac{1}{24}$

Answer : C

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD is 2 × 5 = 10.

Step 2:

Rewriting as equivalent fractions

$\frac{5}{10}$ + $\frac{2}{10}$ = $\frac{(5+2)}{10}$ = $\frac{7}{10}$

Step 3:

So, $\frac{1}{2}$ + $\frac{1}{5}$ = $\frac{7}{10}$

Q 10 - Subtract $\frac{1}{8}$ − $\frac{1}{9}$

Answer : A

Explanation

Step 1:

Here the fractions have unlike denominators. So we find LCD.

LCD is 8 × 9 = 72.

Step 2:

Rewriting as equivalent fractions

$\frac{9}{72}$ − $\frac{8}{72}$ = $\frac{(9-8)}{72}$ = $\frac{1}{72}$

Step 3:

So, $\frac{1}{8}$ − $\frac{1}{9}$ = $\frac{1}{72}$

addition_or_subtraction_of_unit_fractions.htm
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