Mrs. Crawford has invested $ 6,000 at 3% interest. How much additional money should she invest at 8% interest so that the total income will be 4% of her total investment?

Scott asked you to make 10 gal. of fruit punch that contains 85% fruit juice by mixing together some Sweet Tropical Fruit Punch and some apple juice. How much of each ingredient do you need if the Sweet Tropical Fruit Punch contain 25% juice?

Thank you so much for your help

2 answers

additional amount --- x

total amount invested = 6000+x
interest from that total at 4% = .04(6000+x)

.03(6000) + .08x = .04(6000+x)
multiply by 100

3(6000+x) + 8x = 4(6000+x)

carry on ...

2nd:

amount of apple juice --- x gal
amount of STFP --- 10-x

x + .25(10-x) = .85(10)

solve for x, etc
Thank you Reiny for your help