In a bag there 10p coins, 20p coins and 50p coins. There are two fewer 20p coins than 10p coins. There are five more 50p coins than 1op coins. Atogether, are 60 coins. Work the value of the 20p coins

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.