What does "y" represent in the given chart?

In which of the following arrangements,the order is not correct according to the property indicated against it?

Find the length of the intercept cut by the pair of lines $2x^2+4xy-4y^2-6x-8y+7=0$ on the $Y$-axis.

Two solutions of $KNO_3$ and $CH_3COOH$ are prepared separately. The molarity of both is $0.1 \ M$ and their osmotic pressures are $P_1$ and $P_2$ respectively. The correct relationship between the osmotic pressures is:

One die and a coin (both unbiased) are tossed simultaneously. The probability of getting $5$ on the top of the die and tail on the coin is

In which plant group is the gametophytic phase reduced,haploid,short-lived,and subterranean?