If $$a^{3} + b^{3}$$ = 19 and a + b = 1, then what is the value of ab?
Given :  $$a^{3} + b^{3}$$ = 19 -----------(i)
Also, $$a+b=1$$ -----------(ii)
Cubing both sides, we get :
=> $$(a+b)^3=(1)^3$$
=> $$a^3+b^3+3ab(a+b)=1$$
Substituting values from equation (i) and (ii)
=> $$19+3ab(1)=1$$
=> $$3ab=1-19=-18$$
=> $$ab=\frac{-18}{3}=-6$$
=> Ans - (B)
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