math
posted by TUHITUHI on .
a merchant buys 2 quantities of rice at rs.60 and rs.40 per kg respectively.he pays at total of rs.10000. on the other hand he had paid a flat rate of rs.50 per kg. he would have paid 10% more. how many kg of each type of rice did he buy?

let the amount of rice at rs.60 be x kg
let the amount of rice at rs.40 be y kg
60x + 40y = 10000 > 3x+2y = 500
50(x+y) = 11000 > x+y = 220 or y = 220x
sub back into the 1st
3x + 2(220x) = 500
3x + 440  2x = 500
x = 60 , then y = 220  60 = 160
check:
60(60) + 160(40) = 10000 , check!
50(220) = 11000 , check!