Home » Past Questions » Mathematics » Find n if log\(_2\) 4 + log\(_2\) 7 — log\(_2\) n = 1

Find n if log\(_2\) 4 + log\(_2\) 7 — log\(_2\) n = 1


Question

Find n if log\(_2\) 4 + log\(_2\) 7 — log\(_2\) n = 1

Options

A)
10
B)
14
C)
27
D)
28

The correct answer is B.

Explanation:

\(\log_2 4 + \log_2 7 - \log_2 n = 1\)
\(\log_2 \left( \cfrac{4 \times 2}{n} \right) = 1\)
\(\log_2 \cfrac{28}{n} = 1\)
\(2^1 = \cfrac{28}{n}\)
\(2n = 28\)
\(n = 14\)

More Past Questions:


Discussion (2)