In march tom had -£165 in his bank account. in april he had -£156. in which month did he have the least amount of money in his account?

He had the least money in march.

-165<-156

Remember that because it is negative, the higher the absolute value, the lower the amount/value. It's the opposite of what most people think :)

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.