3. How many 3 digit numbers are divisible by 17? Write a function to print them and return the sum. (The sum being the sum of the 3 digit numbers that are divisible by 17).

4. Write a program that does the following to an image:

changes black pixels to white and white pixels to black

for non-black and non-white pixels, do the following:

reduce the red by 50% if the value of red is above 200

reduce the red by 20% if the value of red is between 100 (inclusive) and 200 (inclusive)

increase the red by 50% if the value of red is below 100

return the total number of pixels increased or decreased by 50% (not including the black & white pixels)

How did you test your program? How do you know that it works? Show a list of test cases that will ensure that every branch of the program is followed.

Using Jython Envirenment for Student

the Q3: I dont know how to sum the answer

Q4, no idea

```
#===============E 3========================
# This allow any number you want
def dvsble(x,y):
for n in range(x,y):
sum = 0
if n%17 ==0:
x = n
sum()
print n
else:
n=n+1
print sum
```

Q4:

```
def color():
pic = makePicture(pickAFile())
for x in range(getWidth(pic)):
for y in range(getHeight(pic)):
px = getPixel(pic,x,y)
color = getColor(px)
if getColor(Color(255,255,255)):
setColor(color,Color(0,0,0))
elif getColor(0,0,0):
getColor(255,255,255)
show(pic)
```