Subject :IMO Class : Class 6

The given table shows the temperature of a country for 7 consecutive hours.

A17 °C

B29 °C

C21 °C

D25 °C

difference in temp is 23-(-6) that is 29 but 0 to be included then the answer is 30. Think I am correct so the answer is 30 but since 30 is not there nearest number is 29