Question

Find the value for ${\left(998\right)}^3$.

• A. 938538392
• B. 940234942
• C. 994011992
• D. 991029942

Answer 1

The correct option is C

994011992

Using the identity ${(a–b)}^3$ = ${\left(a\right)}^3-{\left(b\right)}^3-3a^{2}b+3a{b}^2$ .

On comparing the identity with the given question, we can re write 998³ as

${(1000–2)}^3$ = ${\left(1000\right)}^3-{\left(2\right)}^3-3{\left(1000\right)}^2\left(2\right)+3\left(1000\right){\left(2\right)}^2$

$=994011992$