Aptitude Question ID : 94354
If a : b = c : d, then $latex \frac{ma+nc}{mb+nd}&s=1$ is not equal to :
[A]$latex \frac{a}{b}&s=1$
[B]$latex \frac{c}{d}&s=1$
[C]$latex \frac{c-a}{b-d}&s=1$
[D]$latex \frac{a+c}{b+d}&s=1$
$latex \mathbf{\frac{a+c}{b+d}}&s=1$
$latex a : b = c : d$
$latex => \frac{a}{b} = \frac{c}{d} = \frac{ma}{mb} = \frac{nc}{nd}&s=1$
$latex => \frac{a+c}{b+d} = \frac{ma+nc}{mb+nd}&s=1$
Hence option [D] is correct answer.