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+31​x+61​x=78. 9x=468\quad 9 x=4689x=468. \quad \dfrac{1}{3} x=17 \frac{1}