Questions

Yes

Let amount of milk removed = 2x litre
So, amount of water added = x litre
Now → (165 − 2x)/x = 5/3
x = 45 lit

Direct Materials doesn't come under Fixed Cost because it vary with changes in the activity level of a business.

Fixed Cost :

A fixed cost is a cost that does not change over the short-term, even if a business experiences changes in its sales volume or other activity levels.

It is of some importance to understand the extent and nature of the fixed costs in a business, since a high fixed-cost level requires a business to maintain a high revenue level in order to avoid generating losses.

Examples of Fixed Cost are:

Insurance, Salaries, Rent, Property Taxes,...

23 chromosomes are in a human gamete.

Human somatic cells have 46 chromosomes(23 pairs) but a gamete(germ cell) gets half the amount, i.e. 23 chromosomes, (one from each pair). There will be half the number of chromosomes an organism has in its somatic cells (all other body cells except gametes).

For example in humans, the somatic cells contain 46 chromosomes which are the diploid number (2n) and each sperm and egg has 23 chromosomes where one of them is the sex chromosome.