Do you believe in the use of blended learning technique? or do think students will not take it seriously and they will be passive?

No , I am believe  in the use of blended learning technique. 

The students will be very serious about it against all expectations 

trial and error method work best. try one and see if it work. when you blend, you dont know which is effective. it is like giving too many pills to a patient, you dont know which served the purpose