The actual price of the mixture

= 140*100/120 = 116.67/kg

Let x be price of the cheaper tea then the the costlier tea is worth 2x. Since the costlier tea is mixed with cheaper in the ratio 2:3.

2/5*(2x) + 3/5*(x) = 116.67

x = 83.33/kg

2x = 166.67.

Therefore the prices of each tea are 166.67/- & 83.33/-.