Test Index

Surds and Indices Practice Test 1

Question : 3 of 40

Marks: +1, -0

10^{2/5} \times 10^{8/5} = 10n

, the value of n is:

Solution:

Concept:

When multiplying powers with the same base, add their exponents:

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

Explanation:

Here,

10^{2/5} \times 10^{8/5} = 10^{2/5 + 8/5}

Add the fractions:

\frac{2}{5}+\frac{8}{5}=\frac{10}{5}=2

So the left side becomes

10^2=100

Thus the intended equation is

10^2=10^n

, giving

n=2

If the equation were literally

100=10n

, then

n=10

, which is not among the options.

Answer:

n=2

, so option A is correct.

Go to Question:

Prev Question

Next Question