Question 988893
50 cups punch, 6% grapefruit;
want mixture be 10% grapefruit;
how many cups grapefruit (juice)?

g, how many cups grapefruit juice to add.


{{{(50*6+g*100)/(50+g)=10}}}


You should understand the equation perfectly, otherwise THAT is how you need any help.  If your understanding is good, then just solve for g.