Weekend Maths Problem My Mum was 27 when I was born. 8 years ago she was twice as old as I shall be in 5 years’ time. How old am I now? Mr Pitts | October 5, 2012 | Numeracy, Word Problems | Numeracy, Word Problems, Year 6 | 2 Comments « Year 5 Homework – 4th October 2012 Year 6 Mini Homework » 2 Comments Olivia copley October 5, 2012 @ 3:21 pm The answer is 4 and a half Reply Mr Pitts October 9, 2012 @ 1:16 pm Not quite Olivia. It’s fairly complicated… x = my age now We know that: x + 27 = Mum’s age now x + 5 = my age in 5 years Mum’s age now – 8 years = Two times my age in 5 years So, x + 27 – 8 = 2(x+5) x +19 = 2x + 10 Subtract x from each side to keep it balanced, but also to remove one x: x + 19 – x = 2x – x + 10 Which means that 19 = x + 10 Again, to keep it balanced, subtract 10 from each side: 9 = x My age is 9 years NOW, and Mum’s age is 9+27=36 years NOW. Check: Eight years ago, Mum was 28. My age in 5 years will be 14. So, her age eight years ago was twice my age in 5 years. Reply Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Notify me of follow-up comments by email. Notify me of new posts by email. This site uses Akismet to reduce spam. Learn how your comment data is processed.

Olivia copley

October 5, 2012@ 3:21 pmThe answer is 4 and a half

Mr Pitts

October 9, 2012@ 1:16 pmNot quite Olivia. It’s fairly complicated…

x = my age now

We know that:

x + 27 = Mum’s age now

x + 5 = my age in 5 years

Mum’s age now – 8 years = Two times my age in 5 years

So, x + 27 – 8 = 2(x+5)

x +19 = 2x + 10

Subtract x from each side to keep it balanced, but also to remove one x:

x + 19 – x = 2x – x + 10

Which means that 19 = x + 10

Again, to keep it balanced, subtract 10 from each side: 9 = x

My age is 9 years NOW, and Mum’s age is 9+27=36 years NOW.

Check:Eight years ago, Mum was 28. My age in 5 years will be 14. So, her age eight years ago was twice my age in 5 years.