Question

Calculate and reduce to simplest form the fraction 6 1/7 + 11/21

Answer 1

$6 \frac{1}{7} = \frac{6 \times 7 + 1}{7} = \frac{42 + 1}{7} = \frac{43}{7} \\ \\ 6 \frac{1}{7} + \frac{11}{21} = \frac{43}{7} + \frac{11}{21} \\ \\ lcm \: of \: denominators(7 \: and \: 21) = 21 \\ \\ = \frac{43 \times 3 + 11 \times 1}{21} \\ \\ = \frac{129 + 11}{21} \\ \\ = \frac{140}{21} = \frac{7 \times 20}{7 \times 3} = \frac{20}{3} \\ \\ = \boxed{ \red{6 \frac{2}{3} }}$

Answer 2

The correct answer is 6 2/3.

In order to find this we first need to give the fractions the same denominator.

6 1/7 = 6 3/21

Now that we have this, we can add the fractions together.

6 3/21 + 11/21 = 6 14/21

And to reduce, you'll notice both parts of the fraction are divisible by 7.. So we divide by a factor of 7.

6 2/3