If a+b+c=8 and a b+b c+c a=20, then a^{3}+b^{3}+c^{3}- 3abc is equal to:

SSC CGL 13 Jun 2019 Shift 1 Paper

Question : 71 of 100

Marks: +1, -0

a+b+c=8

and

a b+b c+c a=20,

then

a^{3}+b^{3}+c^{3}-

3abc is equal to:

Solution:

put

c=0

a+b=8

a b=20

a^{3}+b^{3}=(a+b)\ [(a+b)^{2}-3 a b\ ]

\⇒(8)[(64)-60]

\⇒8 \×4=32

Go to Question:

Prev Question

Next Question