by shivamtripathi22 | Mar 23, 2022 | Uncategorized
(Q). In a class of 12 students 7 are boys and rest are girls. In how many ways students can be selected for a project such that at least 2 boys & 2 girls are selected?Solution:-Number of ways of selecting at least 2 boys= ⁷C₂ + ⁷C₃ + ⁷C₄ + ⁷C₅ + ⁷C₆ + ⁷C₇= (⁷C₀...
by shivamtripathi22 | Mar 23, 2022 | Uncategorized
(Q). In a class of 12 students 7 are boy & rest are girls. In how many ways students can be selected for the project such that at least 1 boy & 1 girl is selected.Solution:-Nuber of ways of selecting one or more boys is (2⁷ – 1) = 127 waysNumber of ways...
by shivamtripathi22 | Mar 22, 2022 | Uncategorized
(Q). A class has 10 students 7 are boys and 3 are girls. In how many ways students can be selected for a project.Solution:-Every student (either boy or girl) has 2 ways of selection → either selected or rejected.∴ students can be selected in 2⁷×2³ = 2¹⁰ = 1024...
by shivamtripathi22 | Mar 22, 2022 | Uncategorized
(Q). How many factors of 1800 other than 1800 are 4 digit number?Solution:-1800 = 2³×3²×5²So except 1800 itself other largest factor is = = 900 → three digitsHence number of four digit factors = 0 ...
by shivamtripathi22 | Mar 22, 2022 | Uncategorized
(Q). Find the number of factors of 1800. Solution:- 1800 = 18×100 = 2×9×4×25 = 2³×3²×5²Hence number of factors = (3+1).(2+1).(2+1) = 4×3×3 = 36 ...
