Question

If 0 stands for the operation "Add and double the sum",

that is a 0 b = 2 (a + b); and

//// stand for "Multiply and halve", that is a ////$b=\frac{1}{2}ab$.

Find the value of (5 //// 4) 0 (7 //// 6)

• A. $117$
• B. $88$
• C. $62$
• D. $31$

Answer 1

The correct option is C $62$

(5 //// 4) 0 (7 //// 6)
$\Rightarrow \left(\frac{5\times 4}{2}\right)0\left(\frac{7\times 6}{2}\right)$
$\Rightarrow \left(10\right)0\left(21\right)$
$\Rightarrow [10+21]\times 2=62$
Hence, option 'C' is correct.