If 78 is divided into three parts which are in the ratio $1:\frac{1}{3}:\frac{1}{6}$, the middle part is
1). $9\frac{1}{3}$
2). 13
3). $17\frac{1}{3}$
4). $18\frac{1}{3}$
RATIO = 1 : $\frac{1}{3}$ : $\frac{1}{6}$ = 6:2:1
Sum of the ratios = 6 + 2+1 = 9
$\therefore$ middle part =$\frac{2}{9}\times78$ = $\frac{52}{3}$= $17\frac{1}{3}$
2. If x:y = 3:4 and y:z = 3:4,then $\frac{x+y+z}{3z}$ is equal to