the expression \( \frac{|a|}{a} = -1 \)if \(a < 0\), and \(+1\), if \(a>0 \)
similarly, \(\frac{b}{|b|} = -1\) if \(b<0\), and \(+1 \)if \(b>0 \)
We can see that each of the fractions in the expressions depend on the sign of the number involved, if number is negative, then that fraction will be -1, if number is positive, then that fraction will be +1
To find maximum number
We need to get as many fractions to be positive as possible
\(\\
a = +1, \frac{|a|}{a} = +1\\
b = -1, \frac{2b}{|b|} = -2\\
c = +1, \frac{3|c|}{c} = +3 \\
d = -1, \frac{4d}{|d|} = -4 \\
abcd = +1, \frac{5|abcd|}{abcd} = +5 \\
\)
Sum = +1 -(-2) + 3 -(-4) +5 = 1+2+3+4+5 = 15, this is the max we can get because all components are positive here
Max = 15To find minimum number, we need to get as many components to be negative as possible,
trying to get all components negative not possible because>>
\(a = -1, \frac{|a|}{a} = -1\\
b = +1, \frac{2b}{|b|} = +2\\
c = -1, \frac{3|c|}{c} = -3 \\
d = +1, \frac{4d}{|d|} = +4 \\
abcd = +1, \frac{5|abcd|}{abcd} = +5 \\
\\
\)
then sum= -1-2-3-4+5 = 5-10 = -5
To get minimum, we can afford having a to be positive, so that we can get abcd = -1,
\(a = +1, \frac{|a|}{a} = +1\\
b = +1, \frac{2b}{|b|} = +2\\
c = -1, \frac{3|c|}{c} = -3 \\
d = +1, \frac{4d}{|d|} = +4 \\
abcd = -1, \frac{5|abcd|}{abcd} = -5\)
then sum = +1-2-3-4-5 = 1-14= -13
Range = 15-(-13) = 15+13 = 28Answer is D