Answer:
Step-by-step explanation:
In No.1
First you find the total number of girls which is 56-20 =36 girls in total
So to get number of boys who watched tennis 20-13=7 boys watched tennis
To get number of girls who didnt watch you do 36-17=19 girls who watched
Then add o get the totals
No.2
First you get the total number of male 80-47=33 males
Next you find the number of females doing phyisics 33-19=14 females
Next you find the number of females doing chemistry by 47-(18 + 14)=15 females
To get the number of males diong chemistry 21-15=6 males
Number of males doing biology 33-(19+6)=8
Then find the remaining totals
2
No. 2 (b)
Because there is a high number of students doing physics and most of them are female
Two trapezoid are similar
so it has some scale factor
look longer base of a big trap is 8 mi,and longer base of shorter trap is 4mi.
so that is half of big trapezoid.
so little trapezoid base should be 1 as big trap's shorter base is 2mi<span />
For this we need to do (1530/3000)*100
1530/3000 is the same as 153/300 which is the same as 51/100
Therefore the total percentage is 0.51*100 = 51%
