Answer
a. 400,
b. no outlier.
Work Step by Step
a. 506, 511, 517, 514, 400, 521
Q1= 506, Q2= 512.5, Q3= 517, IQR=11,
Range to check outliers: $506-1.5\times11$ to $517+1.5\times11$ or $489.5-533.5$
There is one outlier at 400
b. 3, 7, 9, 6, 8, 10, 14, 16, 20, 12
Q1= 7, Q2= 9.5, Q3 =14, IQR=7
Range to check outliers: $7-1.5\times7$ to $14+1.5\times7$ or $(-3.5 ,24.5)$
No outlier.
