I have two kinds of candy,one which is selling at P8.00 per kilo and other at P6.00 per kilo. How many kilos of the P6.00 candy can i mix with 20 kilos of the P8.00 kilo candy to have a mixture that i can sell at P7.00 per kilo?
just add up the value of the parts. They have to sum to the value of the whole.
8.00(20) + 6.00x = 7.00(20+x)
Actually, this one is easy -- since 7.00 is the average of 6 and 8, you need equal amounts of the two kinds.