Problem: A farmer divides his herd of n‾\underline{n}n​ cows among his four sons so that one son gets onehalf the herd, a second son, one-fourth, a third son one-fifth, and the fourth son, 777 cows. Then n‾\underline{n}n​ is:
Answer Choices:
A. 808080
B. 100100100
C. 140140140
D. 180180180
E. 240240240 Solution:
n=12n+14n+15n+7.n=140n=\dfrac{1}{2} n+\dfrac{1}{4} n+\dfrac{1}{5} n+7 . \quad n=140n=21​n+41​n+51​n+7.n=140