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Let the Number of boys and Girls who appeared in exam be x and y respectively, So, according to question- Number of boys passed in exam = [(100 - 20) × x]/100 = 0.80x Number of girls passed in exam = [(100 - 15) × y]/100 = 0.85y Condition (1) - ⇒ 0.80x = 0.85y + 70 ⇒ 0.80x - 0.85y = 70 ...(i) Condition (2) - Total failed students = 90 ⇒ 0.20x + 0.15y = 90 ...(ii) From eqn (1) - [4 × eqn (ii)] ⇒ (-0.85y) - 0.60y = 70 - 360 ⇒ 1.45y = 290 ⇒ y = 200 Put this value in eqn (i) ⇒ 0.80x = 0.85 × 200 + 70 ⇒ 0.80x = 170 + 70 = 240 ⇒ x = 300 So, total number of students appeared in exam = 300 + 200 = 500.
5, 5, 15, 75, ?, 4725
8, 24, 48, 80, ?, 168
8 13 36 123 ? 2585
250, 279, 311, 349, 396, ?
840, 2520, 630, 3150, ?, 3675
12, 24, 46, 78, 120, ?
81, 41, 42, 64.5, ?, 330
8, 58, 75, 94, 115, ?
200 ? 96 38.4 7.68 0