Isaac has 10 coins in a bowl. There are 4 quarters, 3 nickles, and the rest are pennies. Without looking, he grabs one coin, puts it back, and then grabs another coin. What is the probability that both coins he grabs are quarters?
4/10*4/10 = 16/100 = 4/25 Is this the correct way to solve this problem?
3/25
2/15
4/25
16/49

Use the graph of the sine function y=2sinθ shown below

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.

3. a sum of $2700 is to be given in the form of 63 prizes. if the prize is of either $100 or $25, find the number of prizes of each type.