Stefan is three years younger than his sister katie. the sum of stefans age three years ago and 2/3 of katies age at that time is 12.how old is katie now. show your work

If x is the age of S

And y is the age of K

So we have x=y+3

And the second equation is x-3 + 2/3)y = 12

We have to solve the system

x-y=3

x+2/3y=15

we find x=10.2 and y=7.2

so Katie is 7 

15% chance.

step-by-step explanation:

3/10 times, the 5 year old will get a tablet. 5/10 times, the 13 yer old will get a tablet. multiply both fractions to get 15/100 times, both would have a tablet.

(hint): the answer is in the question.