Question 328741
{{{(A+B+C+D)/4=82}}}
1.{{{A+B+C+D=328}}}
Let {{{A}}} be the lowest grade.
{{{(B+C+D)/3=86}}}
2.{{{B+C+D=258}}}
Substitute eq. 2 into eq. 1,
{{{A+258=328}}}
{{{A=70}}}
The lowest grade was a 70.