20•20+50:10

To solve the expression \(20 \cdot 20 + 50 \div 10\), follow the order of operations (PEMDAS/BODMAS):

1. Multiplication: \(20 \cdot 20 = 400\)
2. Division: \(50 \div 10 = 5\)
3. Addition: \(400 + 5 = 405\)

Thus, the final result is \(405\).