<Dl> <Dd> P (X = 1) = (10 1) × 0.01 1 × 0.99 9 (\ displaystyle P (X = 1) = (\ binom (10) (1)) \ times 0.01 ^ (1) \ times 0.99 ^ (9)) <Dl> <Dd> ≈ 10 × 0.01 × 0.914 (\ displaystyle \ approx 10 \ times 0.01 \ times 0.914) </Dd> <Dd> ≈ 0.0914 (\ displaystyle \ approx 0.0914 \,) </Dd> </Dl> </Dd> </Dl> <Dd> P (X = 1) = (10 1) × 0.01 1 × 0.99 9 (\ displaystyle P (X = 1) = (\ binom (10) (1)) \ times 0.01 ^ (1) \ times 0.99 ^ (9)) <Dl> <Dd> ≈ 10 × 0.01 × 0.914 (\ displaystyle \ approx 10 \ times 0.01 \ times 0.914) </Dd> <Dd> ≈ 0.0914 (\ displaystyle \ approx 0.0914 \,) </Dd> </Dl> </Dd> <Dl> <Dd> ≈ 10 × 0.01 × 0.914 (\ displaystyle \ approx 10 \ times 0.01 \ times 0.914) </Dd> <Dd> ≈ 0.0914 (\ displaystyle \ approx 0.0914 \,) </Dd> </Dl> <Dd> ≈ 10 × 0.01 × 0.914 (\ displaystyle \ approx 10 \ times 0.01 \ times 0.914) </Dd>

What is the standard time considered for normal flood return period for a bridge design