Thank you Archie,

I'm on really old methods:

"Cross multiply and divide by the one opposite the question mark"

But, my problem was which figure to take as the 100% starting point, which you have so clearly explained is the initial amount.

This, compounded with the fact that (if I've done it right) the answer is just over an 80% increase on the insurance in 2 years, unsurprisingly made me doubt my answer.

And now, I have the difficult task of debating this with the insurance company.

Best regards,

Gerts.