F.3math!help!

1.Consider the following set of data arranged in ascending order:12,13,23,x,45,y,62,63
If the median and the mode are 39 and 45 respectively,find the values of x and y

2.The mean weightof 30 boys and 20 girls is 53 kg If the mean weightof the girls is 46 kg Find the mean weight of the boys.(3 significant...)

3.The mean of a set of nine data is calculated as 54.Later ,it is found
that one datum 102 is wrongly typed as 39.Find the correct mean of the data

4.The mean of a set of 15 data is87.If a data 0 is added,Find the new mean

5.B is the top of a tree with height 8m.A is the top of another tree with
height 20m.If the two trees are 32m apart Find the angle of depression of B from A.(3 significant)

6.ABCF is a quadrilateral .D,E,G and H are midpoints od AB,BC,AF and CF respectively,Prove that DEHG id a parallelogram

7.IF the sum of three consecutive odd integers is greater than 190,find the least possible of the three integers

8.If the perimeter of a rectangle is at most 104cm and the difference between the length and the width of the rectangle is 4cm,find
(a)the maximum width of the rectangle(Hint:Let x be the length of the rectangle first,and then set up an equation)

(b)the maximum area of the rectangle

9. Eight times a number is smaller than triple of that number by more than eleven .Find the largest possible integral value of the number