Current Electricity

A moving coil galvanometer is converted into an ammeter, reading upto \(0.04 \mathrm{~A}\) by connecting a shunt of resistance '\(3 \mathrm{r}\)' across it and then into an ammeter reading upto \(0.8 \mathrm{~A}\), when a shunt of resistance '\(r\)' is connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used?