Questions

If some action has started in the past and is still continuing, then present perfect continuous tense should be used instead of present continuous tense. So, the phrase ‘am waiting’ needs to be replaced with ‘have been waiting’ to make the sentence contextually correct. Thus, the correct formation would be, ‘I have been waiting for three –quarters of an hour’.

Both warmth and moisture reduce the density of air and hence its pressure is high.

A concentrated solution will contain the most solute molecules per solvent molecules.

Here in the given options,

1)  6/10 = 0.6

2) 20.5/50 = 0.41

3) 30/120 = 0.25

4) 2.6/2 = 1.3

Hence, option D) is most concentrated.

The indifference curves cannot intersect each other.

Higher indifference curve represents a higher level of satisfaction because higher IC means a bundle consisting more of both the goods or same quantity of one good n more quantity of the other good .Hence statement 2 is correct and 3 is incorrect.

Indifference curves is convex to the point of origin because of diminishing Marginal Rate of Substitution.