Number System
Sum of square of first number and cube of second number together is 568. Also square of the second number is 15 less than square of 8. What is the value of three-fifth of the first number ?
Let the first number be x and the second number be y.∴ y² = 82 - 15 = 64 - 15 = 49∴ y = 7∴ x² + 73 = 568= x² + 343 = 568= x² + 568 - 343 = 225∴ x = √225 = 15∴ 15 x 3/5 = 9
Total balls = 5 + 4 + 4 = 13∴ n(S) = 13C3 = 2862 blue balls can be selected from 4 balls in 4C2 = 6 ways and the remaining one ball is to be selected from 9 balls in 9C1 = 9 ways ∴ n(E) = 6 x 9∴ P(E) = 6 x 9/286 = 27/143
Let the consecutive odd number be x, x + 2, x + 4 and x + 6 respectively.According to the question x + x + 2 + x + 4 + x + 6 = 104 = 4x + 12 = 104 = 4x = 104 - 12 = 92∴ x = 92/4 = 23∴ Required number = x + 4= 23 + 4 = 27
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