Question

How many times smaller is 2 × 10 to the negative 8th power than 4 × 10 to the negative 7 power?

A. 20
B. 200
C. 0.2
D. 2,000

Answer 1

The values are

• 2×10-⁸ and 4×01^{-7}

Divide to find how many times smaller

• 4/2×10^{-7+8}
• 2(10)
• 20times

Answer 2

• A. 20

Explanation:

How many times smaller is 2 × 10⁻⁸ than 4 × 10⁻⁷ ?

Rewrite the numbers with the same power of 10:

• 2 × 10⁻⁸ and 40 × 10⁻⁸

Divide the second number by the first, cancel the powers as they are same:

• 40/2 = 20

Correct option is A