Problem: If 787878 is divided into three parts which are proportional to 1,13,161, \dfrac{1}{3}, \dfrac{1}{6}1,31,61, the middle part is:
Answer Choices:
A. 9139 \dfrac{1}{3}931 B. 131313 C. 171317 \dfrac{1}{3}1731 D. 181318 \dfrac{1}{3}1831 E. 262626 Solution:
x+13x+16x=78x+\dfrac{1}{3} x+\dfrac{1}{6} x=78x+31x+61x=78. 9x=468\quad 9 x=4689x=468. \quad \dfrac{1}{3} x=17 \frac{1}