Question

$\mathrm{Consider}\mathrm{the}\mathrm{following}\mathrm{addition}\mathrm{and}\mathrm{match}\mathrm{the}\mathrm{unknown}\mathrm{digits}\mathrm{with}\mathrm{the}\mathrm{correct}\mathrm{values}$
$\begin{array}{cccc}& Q& 0& 4\\ +& A& C& Q\\ & 9& 2& 1\end{array}$

• A. 7
• B. 2
• C. 1

Answer 1

A, C and Q are all single digit numbers. Since the units digit of the answer is 1, the added value of 4 and Q must end with '1' and this is only possible when Q=7.

Now, 7+4=11 and the carry '1' will add to the digits in the tens place. Hence, the value of C+0+1 should end with 2, and this is possible when C=1 only.

The value of Q is 7, and 7+A is 9. Therefore, the value of A is 2.