Higher November 2020 Paper 3 Q13
13
(a) Simplify \(\quad \dfrac{25a}{8} \times \dfrac{2a}{5}\)
Give your answer as a single fraction in its simplest form. [2 marks]
(b) Sofia is trying to simplify \(\quad \dfrac{6c + 10}{2}\)
Her method is
divide \(6c\) by 2
then
add 10
Evaluate her method. [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{5a^2}{4}\) or \(1\dfrac{1}{4}a^2\) | B2 | B1 correct single fraction not in simplest form eg \(\dfrac{50a^2}{40}\) or \(1.25a^2\) or \(\dfrac{5}{4}a\) or \(\dfrac{5a}{4}\) or \(1\dfrac{1}{4}a\) |
Additional guidance
| Final answer \(1.25a^2\) (even if \(\dfrac{5a^2}{4}\) seen in working) | B1 |
| Answer | Mark | Comments |
|---|---|---|
| Valid evaluation | B1 | eg she needs to divide 10 by 2 or the answer should be \(3c + 5\) |
Additional guidance
| Do not award marks when an incorrect statement or incorrect algebra is seen with a correct statement or correct algebra | |
| She needs to add 5 not 10 | B1 |
| She must divide all of the numerator by 2 | B1 |
| She must divide everything by 2 | B1 |
| She should divide both sides by 2 | B0 |
| She needs to work out \(6c + 10\) then divide by 2 | B0 |
| Her method is wrong | B0 |
| \(3c + 5\) alone | B0 |