Answer:
Well, if you look up countries with the highest birth rates, also those countries poverty rates and what class the majority of the people are in then you should have a better understanding. Also, education is not passed through genes it is learned through expirience and being taught. Also being rich vs being poor probably doesn't have that big of an effect either. It is the living conditions.
Explanation:
Answer:
Yellow light is a combination of red and green light. So combining blue with yellow light is like combining blue light with red and green light. The result of combining these three primary colors of light is to produce white light.
Answer:
1) 
2) 
3) 

Explanation:
Given:
width of river, 
speed of stream with respect to the ground, 
speed of the swimmer with respect to water, 
<u>Now the resultant of the two velocities perpendicular to each other:</u>



<u>Now the angle of the resultant velocity form the vertical:</u>



- Now the distance swam by the swimmer in this direction be d.
so,



Now the distance swept downward:



2)
On swimming 37° upstream:
<u>The velocity component of stream cancelled by the swimmer:</u>



<u>Now the net effective speed of stream sweeping the swimmer:</u>



<u>The component of swimmer's velocity heading directly towards the opposite bank:</u>



<u>Now the angle of the resultant velocity of the swimmer from the normal to the stream</u>:



- Now let the distance swam in this direction be d'.



<u>Now the distance swept downstream:</u>



3)
Time taken in crossing the rive in case 1:



Time taken in crossing the rive in case 2:



The first factor is wind speed, the second factor is wind duration, and the last factor is the fetch, the distance over which the wind blows without a change in direction.
all these factors determines the strength of a wave.
hope this helps :)