Question

Find an approximate value of $\left(0.99\right)$ ${}^5$ using the first three terms of its binomial expansion.

• A. $0.591$
• B. $0.951$
• C. $0.195$
• D. None

Answer 1

The correct option is B $0.951$

We can write it as $(0.99{)}^5=(1-0.01{)}^5$

$=1{-}^5{C}_1\times \left(0.01\right){+}^5{C}_2\times (0.01{)}^2$................
$=1-0.05+10\times 0.0001.................$

$=1.001-0.05=0.951$