Answer:
51% of the farm's grain is organic
Explanation:
23. The overall percentage is ...
(fraction of grain that is wheat)×(fraction of wheat that is organic) + ...
(fraction of grain that is barley)×(fraction of barley that is organic)
= 0.70×0.60 + (1 -0.70)×0.30
= 0.42 + 0.09 = 0.51
= 51%