Case17. Given an integer in the range 10-40, which determines the number of training assignments on a certain topic. Output a string-description of the specified number of tasks, for example: 18 - "eighteen study assignments", 23 - "twenty three study assignments", 31 - "thirty one study assignments".

Solution in Python 3:

import random

dcat = {
    11 : 'eleven',
    12 : 'twelve',
    13 : 'thirteen',
    14 : 'fourteen',
    15 : 'fifteen',
    16 : 'sixteen',
    17 : 'seventeen',
    18 : 'eighteen',
    19 : 'nineteen',
}

desyatki = {
    10 : 'ten',
    20 : 'twenty',
    30 : 'thirty',
    40 : 'forty'
}

edinici  = {
    1 : 'one',
    2 : 'two',
    3 : 'three',
    4 : 'four',
    5 : 'five',
    6 : 'six',
    7 : 'seven',
    8 : 'eight',
    9 : 'nine'
}

try:
    N = random.randrange(10,41)
    #N = 40
    print("N = ",N)
    if 10 < N and N < 20:
        print("{0} study assignments".format(dcat[N]))
    else:
        r = N%10
        print("r = ",r)
        if r == 0:
            print("{0} study assignments".format(desyatki[N]))
        else:
            q = int(N/10)*10
            print("q = ",q)
            print("{0} {1} study assignments".format(desyatki[q], edinici[r]))

except KeyError as e:
    print('Error')