Questions

There are 60 minutes in an hour.

In ¾ of an hour there are (60 × ¾) minutes = 45 minutes.

In ¾ of an hour there are (60 × 45) seconds = 2700 seconds.

Siren sounds for every 5 seconds.

In 2700 seconds = 2700/5 = 540 times.

The count start after the first sound, the Siren will sound 541 times in ¾ of an hour.

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

Hence, CF4 represents a Non-polar molecule.

Ichthyology is the branch of biology devoted to the study of fish.

It is also known as Fish science which includes bony fishes (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha).

In short, Democracy is a government "of the people, by the people, and for the people."

Definition :

Democracy "is government by the people in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system." 

The conditions of a democratic election are:

* Every citizen should have one vote ad every vote should have an equal value.

* Voters choose from the political parties and candidates should be free to contest elections giving the voters a real choice.

* Elections should be held at regular intervals.

* The candidate preferred by the people should get elected.

* Elections should be conducted in free and fair manner where people can choose as they really wish.

Let the required number of bottles be x.

More weavers, More mats (Direct Proportion)

More days, More mats (Direct Proportion)

$$\begin{gathered} Wavers 4:8 \\ Days 4:8 \end{gathered}$$  :: 4:x

 4 x 4 x x = 8 x 8 x 4

=> x= 8*8*44*4

=>  x = 16.