Question

The mean and median of 100 observation are 50 and 52 respectively the value of the largest observation is 100 it was later found that it is 110 not 100find trie mean and median

Answer 1

mean = 50. 
ie ∑x / 100 = 50 , where x are the observations
therefore ∑x = 50 * 100 = 5000
now, 100 is actually 110, so 

new ∑x =  5000 - 100 + 110 
new ∑x = 5010 
new mean = new∑x/ 100 = 5010/100 = 50.1 

new median = 52, as median remains unchanged as it is the middlemost observation, hence 110 has no effect on the median as it is the highest observation