$600 \, gm$ of sugar solution contains $40 \%$ sugar. How much sugar should be added to make the concentration $50 \%$ in the solution? (in $gm$)

The ratio in which tea costing $Rs. 192$ per $kg$ is to be mixed with tea costing $Rs. 150$ per $kg$ so that the mixed tea,when sold for $Rs. 194.40$ per $kg$,gives a profit of $20\%$,is:

$A$ tea seller mixes three qualities of tea $T_{1}, T_{2}$,and $T_{3}$ priced at $Rs. 74$ per kg,$Rs. 68$ per kg,and $Rs. 63$ per kg in the ratio of $1:2:4$. He added some more quantity of $T_{1}$ to $4$ kg of this mixture. He sold this new mixture for $Rs. 84$ per kg,thereby making a profit of $20\%$. How much of $T_{1}$ did he mix with the mixture? (in kg)

Two liquids are mixed in the ratio of $3: 2$ and the mixture is sold at $Rs. 11$ per litre at a $10 \%$ profit. If the $1$st liquid costs $Rs. 2$ more per litre than the second,what is the cost per litre of the second liquid (in $.80$)? (in $Rs.$)

In $50\, g$ alloy of gold and silver,the gold is $80\%$ by weight. How much gold should be mixed to this alloy,so that the weight of gold would become $95\%$? (in $g$)

In what ratio must a person mix three kinds of wheat costing $Rs. 1.20$,$Rs. 1.44$ and $Rs. 1.74$ per $kg$ so that the mixture may be worth $Rs. 1.41$ per $kg$?