If '+' means '÷', '−' means '×', '×' means '+' and '÷' means '−', then 6 ÷ 10 − 4 × 12 + 6 = ?

If '+' means '×', '−' means '÷', '×' means '+' and '÷' means '−', then which one of the following equations is correct?

Find the missing terms: 2, 15, 4, 12, 6, 7, ?, ?

If 1² + 2² + 3² + ... + n² = [n(n+1)(2n+1)] / 6, find the value of 5² + 6² + 7² + ... + 10².

Find the missing number in the following – 2, 3, 4, 6, 6, 9, 8, 12, 10, ............, 12, 18, 14, 21, 16, 24

Find the missing value: 4, 23, 60, 121, ?