I have to remove a row in datatable

I have a datatable

For ex:
Date method rate
12/31/2020. abc. rate1
12/31/2020. abc.
12/31/2019. bcc
Here i have to consider the first two rows since it has same date and method then I have to remove the rate column which does not have rate value

In this above sernario i have to remove the second row

If both the two have no value in rate column i have to keep the two columns

in general we can do it by grouping the data on the date column

it is describing a NON-LINQ and a LINQ approach