In what proportion must tea worth $75$ paise per packet be mixed with tea worth ₹$5.50$ per packet so that the mixture may cost ₹$4.50$ per packet?

There are two containers of equal capacity. The ratio of milk to water in the first container is $3:1$,and in the second container,it is $5:2$. If they are mixed,the ratio of milk to water in the mixture will be:

The cost of Type $1$ rice is $Rs. 15$ per $kg$ and Type $2$ rice is $Rs. 20$ per $kg$. If both Type $1$ and Type $2$ are mixed in the ratio of $2:3$,then the price per $kg$ of the mixed variety of rice is? (in $Rs.$)

$400 \, gm$ of salt solution has $40 \%$ salt in it. How much salt should be added to make the concentration $50 \%$ in the solution?

$A$ man buys two cows for ₹$1350$ and sells one,so as to lose $6 \%,$ and the other so as to gain $7.5 \%$ and on the whole he neither gains nor loses. What does each cow cost?

How many $kg$ of salt at $42$ $P$ per $kg$ must a man mix with $25 \, kg$ of salt at $24$ $P$ per $kg$,so that he may,on selling the mixture at $40$ $P$ per $kg$,gain $25 \%$ on the outlay?