Question

By using the digits 1, 3, 5, 7, the sum of all the 4 digits numbers formed in which repetitions of digits is not allowed , is –

• A. 106656
• B. 101276
• C. 117312
• D. None of these

Answer 1

Answer: (A)

106656

Answer 2

Sum = $\begin{matrix} 4–1 \end{matrix}$ × (1 + 3 + 5 + 7) × 1111

= 6 × 16 × 1111 = 106656