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You haven't got enough information to answer that question. If you are 30nm east of the NDB and you are going to make a 30° intercept of a particular track, you will have to know what track you are trying to intercept. The question hasn't told you that.
To make a 30° intercept of the 300°M track from the left, you would need a heading that is 30° to the left of 300°M. So turn onto a heading of 270°M and fly until the ADF reads +30 from (210°R or 30° off the tail).