Question

which no. is different in 35,45,60,75,80

Answer 1

75 is right answer
35+10=45
45+15=60
60+20=80

Answer 2

75 is correct one.

because
35-7×5
45-5×3×3
60-5×3×4
75-5×5×3
80-5×16

all have 1 factor of 5 while 75 have two factors of 5