Mathematics · Time and Work

Riya can complete a piece of work in 18 days, and Meera in 24 days. Meena alone can complete it in 25 days, and Reena alone in 30 days. They all decided to work one by one. Riya started the work and worked for a quarter of the day, then Meera worked for a quarter of the day, then Meena worked for a quarter of the day, and then Reena worked for the remaining quarter. This cycle was repeated until the work was finished. Who was working when the work was finished?