We have two functions, one which converts rubles to USD and one which converts USD to euros. If we want to convert from rubles to euros, we could just convert it to USD and then euroes.
2000₽ ⇒ USD

$68 USD ⇒ €

Extra: If you wanted, you could create a function to convert rubles into euroes.
Just substitute that 0.034r for d in e(d) = 0.76d and...
10 because she already knows 3 so then you divide 80 (number of words she hasn’t learned) by 8 (the number of weeks) and you get 10.
The hourly rate is the slope or $15 in this case.