June 2022 Paper 1 Q1
1 \((x + 1)\) is increased by 20%
Its value is now the same as \(\quad (x + 6)\)
Work out the value of \(x\). [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| 1.2 or \(\dfrac{6}{5}\) | M1 | oe could be seen in calculation (120% is not M1 – something needs to have been done with it) \(\dfrac{5}{6}\) if used correctly could be an oe. Don’t award just for \(\dfrac{5}{6}\) seen |
| \(1.2x + 1.2 = x + 6\) or \(0.2x + 1.2 = 6\) or \(0.2x = 4.8\) | M1dep | oe but must have expanded brackets missing brackets need to be recovered |
| 24 | A1 | |
| Alternative method 2 | ||
| \((x + 1) + \dfrac{(x + 1)}{5}\) | M1 | oe |
| \(\dfrac{(x + 1)}{5} = 5\) or \((x + 1) = 25\) | M1dep | oe eg could be written as 20% of \((x + 1) = 5\) |
| 24 | A1 | |
Additional guidance
| 20% = 5 or 100% = 25 \(1.2(x + 1) = x + 6\) then \(1.2x + 1 = x + 6\) would not gain second M mark | SC1 |