The average age of Kofi, Ama and their child 4 years ago was 20 years and that of Ama and the Kofi 5 years ago was 30 years. The present age of the child is?

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.

You get 1 inch of snow every 2 hours

The answer to your question is 2