A new kind of treatment for breast cancer is introduced. An experimental analysis is needed to study the effect of the new treatment. You find 20 women with breast cancer and want to divide them randomly into a treatment group and a control group, each of size 10. One medicine used in the new treatment is related to cardiovascular diseases, so you need to take it into consideration. If it is known that 7 out of the 20 women have a history of cardiovascular disease what is the probability that there are 3 women in the treatment group with a history of cardiovascular disease?