How many no of cement bag in m20?

In an M20 concrete mix, which has a ratio of 1:1.5:3 (cement: sand: aggregates), approximately 7 to 8 bags of cement are needed for one cubic meter of concrete. This translates to about 350 to 400 kg of cement, considering a standard 50 kg bag. The exact number may vary based on factors like waste, mix adjustments, and specific project requirements.