Getting slightly different answer

Q5. Huffman 5
Suppose the letters a, b, c, d, e, f have probabilities 1/2, 1/4, 1/8, 1/16, 1/32, 1/32 respectively. What is the average length of Huffman codes?

3

2.1875

2.25

1.19375

in this i am getting answer as 1.9… can you please solve and give the solution so i may know where i am going wrong