50 points!!!!!
In Mr. Tarkanian history class each student chooses two of the topics listed in the chart above for their papers. how many different pairs can Juliana choose?

year invention
1807 steamboat
1825 photography
1837 telegraph
1846 sewing machine
1869 hydroelectric power
1879 telephone
1888 light bulb
1890 rabies vaccine
1897 airplane