An oil painting is 16 years older than a watercolor by the same artist. the oil painting is also three times older the the watercolor. how old is each? choices for the watercolor, s age: 4,8,12

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

Hi, can anyone show me how to do this problem? 100 points for this. in advance

The mean of 10 values is 19. if further 5 values areincluded the mean becomes 20. what is the meanthese five additional values? a) 10b) 15c) 11d) 22