For the application of %2 – distribution, what is the condition for the expected cell frequency? when pooling is made done in testing of goodness of fit?

For the application of %2 – distribution, what is the condition for

1.	For the application of %2 – distribution, what is the condition for the expected cell frequency? when pooling is made done in testing of goodness of fit?
Answer» Each cell frequency ie. E, is ≥ 5.