Question

A jeweller has bars of 18-carat gold and 12-carat gold. How much of each must be melted together to obtain a bar of 16-carat gold weighing 120 grams? (pure gold 24-carat)

Answer 1

Let quantity of 18carat gold be x
" " " 12 " " " y
X+ Y=120 ---i
18x+12y=16*120
3x +2y =320-----ii
Subtracting ii from i
3x+3y=360
3x+2y=320
y=40
Substituting. ..
X+y =120
X+40=120
X=120-40=80
Quantity of 18 Carat gold = 80gm
" " 16 " " = 40gm

Answer 2

Answer: let him take x gram 18 carat and y gram 12 carat gold.

So x+y=120--(1)

18x+12y=16×120--(2)

Subtracting equation 2 from 1

18x+12y=1920

12x+12y=1440

6x=480

x= 80

So y=120-x(x+y=120)

y= 120-80

y=40

Ans:- 80 gram of 18 carat gold and 40gram of 12carat gold.

Step-by-step explanation: