Ruby でやってみました｡

def get_expected_value(n, hit, need)

 random = Random.new

 data = []
 20000.times {
 a = []
 hit.times {
 a << random.rand(1..n)
 }

 data << a.sort[need - 1]
 }

 sum = data.inject(0) { |s, i| s += i }

 sum / data.length.to_f
end

def challenge(n, hit, need)
 data = []
 5.times {
 ev = get_expected_value(n, hit, need)
 data << ev
 puts "#{hit} / #{n} : #{need} --> #{ev}"
 }
 puts "AVERAGE : #{hit} / #{n} : #{need} --> #{data.inject(0) { |s, i| s += i } / data.length.to_f }\n\n"
end

challenge(100, 2, 1)
challenge(100, 2, 2)
challenge(100, 5, 1)
challenge(100, 5, 2)

厳密ではないんですが､全体の枚数に比べて当たりの数が少ないので､問題ないでしょう｡
出力は､こんな感じ｡

2 / 100 : 1 --> 33.88975
2 / 100 : 1 --> 33.91605
2 / 100 : 1 --> 33.7368
2 / 100 : 1 --> 33.84725
2 / 100 : 1 --> 33.8828
AVERAGE : 2 / 100 : 1 --> 33.854530000000004

2 / 100 : 2 --> 67.1916
2 / 100 : 2 --> 66.86195
2 / 100 : 2 --> 67.00155
2 / 100 : 2 --> 67.2567
2 / 100 : 2 --> 66.7357
AVERAGE : 2 / 100 : 2 --> 67.00949999999999

5 / 100 : 1 --> 17.17825
5 / 100 : 1 --> 17.27755
5 / 100 : 1 --> 17.26575
5 / 100 : 1 --> 17.24345
5 / 100 : 1 --> 17.0687
AVERAGE : 5 / 100 : 1 --> 17.206739999999996

5 / 100 : 2 --> 33.84685
5 / 100 : 2 --> 33.762
5 / 100 : 2 --> 33.84545
5 / 100 : 2 --> 33.9635
5 / 100 : 2 --> 33.8712
AVERAGE : 5 / 100 : 2 --> 33.8578

まとめると､こんな感じです｡