Question

The addition of number $6.65\times 10^4$ and $8.95\times 10^3$ and substraction of numbers $2.5\times 10^{-2}-4.8\times 10^{-3}$, respectively in terms of scientific notation will be

• A. $7.545\times 10^4,2.02\times 10^{-2}$
• B. $75.43\times 10^3,2.02\times 10^{-3}$
• C. $745.5\times 10^2,2.02\times 10^{-1}$
• D. $75.45\times 10^0,2.02\times 10^0$

Answer 1

Answer: (A)

The addition of number
$6.65\times 10^4+8.95\times 10^3$
$=(6.65+0.895)\times 10^4=7.545\times 10^4$
Also, substraction of numbers
$2.5\times 10^{-2}-4.8\times 10^{-3}$
$=2.5\times 10^{-2}-\left(0.48\times 10^{-2}\right)$
$=2.02\times 10^{-2}$
The scientific notation will be $7.545\times 10^4$
and $2.02\times 10^{-2}$ respectively.