Question

pen price 10 rupees , pencil price 2 rupees and chocolate price 50 paisa . how much thing we bought then we pay 100 rupees and also bought 100 thing

Answer 1

let number of pen be x
pencil y
and chocolate z
$\\ 10x + 2y + 0.5z = 100 \\ x + y + z = 100 \\ 20x + 4y + z = 200 \\ substract \: second \: from \: third \: we \: get \\ 19x + 3y = 100 \\ now \: some \: hit \: trial \: work \\ put \: x = 1 \: we \: get \: y = 27 \\ nd \: z = 72$ it can have more than one solution