Option (c) is correct

For School C:-

Failed students in 2020 = (7/15) x 1620 = 756

Failed students in 2021 = (4/11) x 1584 = 576

Failed students in 2022 = (3/7) x 1274 = 546

Hence required average = (756 + 576 + 546 )/3 = 1878/3 = 626

विकल्प (c) सही है।

स्कूल C के लिए:-

2020 में असफल छात्र = 7/15× 1620 = 756

2021 में असफल छात्र = 4/11× 1584 = 576

2022 में असफल छात्र = 3/7× 1274 = 546

अतः असफलता औसत = (756 + 576 + 546 )/3 = 1878/3 = 626