Question

Find the product of 21 and (6.3 · 10-4).

A) 0.1323 · 10-1
B) 1.323 · 10-3
C) 1.323 · 10-2
D) 1.323 · 102

Answer 1

I don't think it'd be any of those, because 21×6.3= 132.3, not any of those others. To solve, you would use distributive property and multiply but I don't understand. I'd guess and say it's B, because that's closest to what I got.

Answer 2

The correct option is C.

Explanation:

The given numbers are 21 and (6.3 · 10⁻⁴).

We need find the product of given numbers.

`Product=21\cdot (6.3\cdot 10^(-4))`

`Product=(21\cdot 6.3)\cdot 10^(-4)`

On simplification we get

`Product=(132.3)\cdot 10^(-4)`

Write the number 132.3 in scientific notation.

`Product=(1.323\cdot 10^2)\cdot 10^(-4)`

Using power property of exponents we get

`Product=1.323\cdot 10^(2-4)`
`[\because x^mx^n=x^(mn)]`

`Product=1.323\cdot 10^(-2)`

The product of given values is
`1.323\cdot 10^(-2)`. Therefore the correct option is C.