One-tenth of the cars in a car park are yellow. Another car arrives and now one-ninth of the cars are yellow.

Question

How many cars are now in the car park?

Answer 1

If there are x cars and y yellow cars, clearly the new car is yellow, since 1/9 > 1/10

y = x/10
y+1 = (x+1)/9

There are now 81 cars, with 9 yellow.

Answer 2

For the code, something like

count=0
for i=1..2000
  with student[i] do {
    read   name,sex,score
    pct = score*5/2
    sub45 = false
    if pct < 45 then
      if sex = "F" then
      count++
      print name
    }
  }
}
print "There were ",count," females scoring below 45%"

Answer 3

81