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The homework for English class was to write a poem. The teacher wants to ask 4 students, 2 boys and 2 sirls, to read their poems for the class. If there are 10 boys and 15 girls, how many different combinations of 2 boys and 2 girls can the teacher select?

The homework for English class was to write a poem. The teacher wants to ask 44 students, 22 boys and 22 sirls, to read their poems for the class. If there are 1010 boys and 1515 girls, how many different combinations of 22 boys and 22 girls can the teacher select?

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Q. The homework for English class was to write a poem. The teacher wants to ask 44 students, 22 boys and 22 sirls, to read their poems for the class. If there are 1010 boys and 1515 girls, how many different combinations of 22 boys and 22 girls can the teacher select?
  1. Boys Combination Calculation: To find the number of combinations of 22 boys out of 1010, we use the combination formula C(n,k)=n!k!(nk)!C(n, k) = \frac{n!}{k!(n-k)!}, where nn is the total number of items, kk is the number of items to choose, and ! denotes factorial.\newlineFor 22 boys out of 1010, the calculation is C(10,2)=10!2!(102)!C(10, 2) = \frac{10!}{2!(10-2)!}.
  2. Boys Combination Result: Calculating C(10,2)C(10, 2) gives us 10!2!×8!=(10×9)(2×1)=45\frac{10!}{2! \times 8!} = \frac{(10 \times 9)}{(2 \times 1)} = 45.\newlineThere are 4545 different ways to choose 22 boys out of 1010.
  3. Girls Combination Calculation: Next, we find the number of combinations of 22 girls out of 1515 using the same combination formula.\newlineFor 22 girls out of 1515, the calculation is C(15,2)=15!(2!(152)!)C(15, 2) = \frac{15!}{(2!(15-2)!)}.
  4. Girls Combination Result: Calculating C(15,2)C(15, 2) gives us rac{15!}{2! imes 13!} = rac{(15 imes 14)}{(2 imes 1)} = 105.\newlineThere are 105105 different ways to choose 22 girls out of 1515.
  5. Total Combinations Calculation: To find the total number of combinations of 22 boys and 22 girls, we multiply the number of combinations for boys by the number of combinations for girls.\newlineThe calculation is 45×10545 \times 105.
  6. Total Combinations Result: Calculating 45×10545 \times 105 gives us 47254725. There are 47254725 different combinations of 22 boys and 22 girls that the teacher can select.

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