please help another one…
Jamie and Karen shared $720. The ratio of the amount Jamie received to the amount that Karen received was 1:5.
Jamie received only $2 notes while Karen received only $5 notes.
Karen took some of her $5 notes and exchanged them for $2 notes of the same value with Jamie.
After the exchange, the ratio of the number of Jamie’s notes to that of the number of Karen’s notes became 1:3.
How many $5 notes did Karen use to exchange for $2 notes with Jamie?