Find the range and the interquartile range of (a) the 20 dry days, (b) the 10 rainy days.

The month, in degrees Celsius: $31, 32, 30, 33, 34$, $33, 31, 29, 28, 30$, $32, 33, 35, 34, 32$, $31, 30, 29, 28, 27$, $29, 31, 32, 33, 31$, $30, 28, 27, 29, 30$. It rained on days $8, 9, 10$, $17$ to $20$ and $27$ to $29$. Range = largest $-$ smallest. Q1 and Q3 are the medians of the lower and upper halves (leave the median out when the count is odd), and IQR $= Q_3 - Q_1$.