As a binomial has two terms and a trinomial has 3 terms.
If all the terms of binomial is different and all the terms of trinomial is also different, and there is no common term between binomial and trinomial then total number of terms in the product of binomial and trinomial will be 6.
→Number terms in the product of binomial and trinomial= number of terms in binomial × Number of terms in trinomial = 2×3 =6
for example, A=p+q and B=a+b+c
A×B= (p+q)(a+b+c)=pa +p b+p c+q a+q b+q c= 6 terms , if there is no like term.
