QZ wrote:
If a is a positive integer and \(y = 3.2\) x \(10^a\), what is the value of y?
1. \(400 < y < 30,000\)
2. \(y^2\) \(=\) \(1.024\) x \(10^7\)
Statement 1: \(a\) cannot be \(1\) or \(2\) because in that case \(y=32\) or \(320 <400\) not possible
\(a\) cannot be \(4\) because in that case \(y=32000>30000\) not possible
so \(a=3\) hence \(y=3.2*10^3\).
SufficientStatement 2: we know \(a\) is positive so \(y>0\)
Take the square root of \(y^2\) and as negative value of \(y\) is not possible so we have only one value for \(y\).
SufficientOption
D