There are 3 sections in a question paper and each section contains 5 questions. A candidate has to answer a total of 5 questions, choosing at least one question from each section. Then the number of ways, in which the candidate can choose the questions, is

Total number of ways
\(={ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_3+{ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_2 \times{ }^5 \mathrm{C}_2 +{ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_3 \times{ }^5 \mathrm{C}_1+{ }^5 \mathrm{C}_2 \times{ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_2 +{ }^5 \mathrm{C}_2 \times{ }^5 \mathrm{C}_2 \times{ }^5 \mathrm{C}_1+{ }^5 \mathrm{C}_3 \times{ }^5 \mathrm{C}_1 \times{ }^5 \mathrm{C}_1 \)
\( =5 \times 5 \times 10+5 \times 10 \times 10+5 \times 10 \times 5 +10 \times 5 \times 10+10 \times 10 \times 5+10 \times 5 \times 5 \)
\( = 250+500+250+500+500+250 \)
\( = 2250\)