Is it possible to cover Badaling Great Wall and Botanical Garden in one day ?

Our family, a group of 4 intend to visit Great wall Badaling on 31st May 2017. If we start early can we also cover the Botanical garden and Buddha temple in the same after noon ? If possible what mode of transport is best ? the S2 train or Bus 877 ? We will be having the transport smart card. If we intent to hire a taxi cab from city to BDL and drop us back at Botanical Garden, how much cost should we expect ? thanking you in advance for the answer.

Narayanan , Kerala India