Include Binary Variable in Constraint

[ramgiitk]

New to PuLP..

I have BInary and Continuous decision variables.

If food k is selected Bk (Binary) =1 otherwise 0 and quantity of the food as Qk (Continuous)

My objective is Min Z = Sum (Bk * Qk * Ck)
Ck is Cost for Food k per quantity selected

Constraint 1 (If selected the quantity should be greater than 1/10)
Bk * (Qk -0.1)>=0

Constraint 2: At most Food 1 and 3 Food should be selected

B1+B3 <=1

Can you please help me wich the step to define these constraints in the Python PuLP?