Consider a function 𝑓: (0,1) → {0, 1} defined as follows. For a real number…

Consider a function 𝑓: (0,1) → {0, 1} defined as follows. For a real number 𝑟 ∈ (0,1) , 𝑓(𝑟) = 1 if the second digit after the decimal point in 𝑟 is one of the four digits 2, 3, 6 and 7. Otherwise, 𝑓(𝑟) is equal to 0. The number of points in (0,1) at which 𝑓 is discontinuous is ___________. (answer in integer)