1. The problem is to multiply two hexadecimal numbers: 2B78 and 3A. 2. Convert each hexadecimal number to decimal. - 2B78 in decimal: $$2 \times 16^3 + 11 \times 16^2 + 7 \times 16^1 + 8 \times 16^0 = 2 \times 4096 + 11 \times 256 + 7 \times 16 + 8 = 8192 + 2816 + 112 + 8 = 11128$$ - 3A in decimal: $$3 \times 16^1 + 10 \times 16^0 = 3 \times 16 + 10 = 48 + 10 = 58$$ 3. Multiply the decimal equivalents: $$11128 \times 58 = 645224$$ 4. Convert the product back to hexadecimal. - Divide 645224 by 16 repeatedly and record remainders: $$645224 \div 16 = 40326 \text{ remainder } 8$$ $$40326 \div 16 = 2520 \text{ remainder } 6$$ $$2520 \div 16 = 157 \text{ remainder } 8$$ $$157 \div 16 = 9 \text{ remainder } 13 (D)$$ $$9 \div 16 = 0 \text{ remainder } 9$$ - Reading remainders from last to first: 9 D 8 6 8 5. Therefore, the product in hexadecimal is $$\boxed{9D868}$$.