Answer:
Tom's mum is 34 years old.
Step-by-step explanation:
So, Tom is 10 years old, and Lizzy is 4/5 Tom's age. What you want to do is convert that fraction into a decimal which leaves you with 0.80. You then have to multiply 0.80 by 10, which gives you 8. After that, all you have to do is multiply 8 by 4.25, which leaves you with 34. This means Tom's mum is 34 years of age.