I've been trying to figure this one out for hours, anyone that can help me...I'd be eternally grateful.

Most mathematics professors love to invest their hard earned money. A recent survey of 150 math professors revealed that

111 invested in stocks;

98 invested in bonds;

100 invested in certificates of deposit;

80 invested in stocks and bonds;

83 invested in bonds and certificates of deposit;

85 invested in stocks and certificates of deposit;

9 did not invest in any of the three.

How many mathematics professors invested in stocks and bonds and certificates of deposit?

Thank you so much!!