Question

1.42 x 107 x 2.81 x 101 = ??

Answer 1

ANSWER

Option A

EXPLANATION

The given product is

$1.42 \times {10}^{7} \times 2.81 \times {10}^{1}$

$1.42 \times 2.81 \times {10}^{7} \times {10}^{1}$

We multiply to get;

$3.9902 \times {10}^{7} \times {10}^{1}$

Recall the product rule

${a}^{m} \times {a}^{n} = {a}^{m + n}$

We apply the product rule to get,

$3.9902 \times {10}^{7 + 1}$

$3.9902 \times {10}^{8}$

Correct to the nearest tenth, we have

$3.99 \times {10}^{8}$

This can also be written as;

$3.99 {e}^{8.00}$

The correct choice is A.