50
40:64 = 50:80
-50
80%=80/100 80/100 x 50 questions = 40 correct answers. therefore 50 - 40 = 10 incorrect answers.
There are many sets of numbers with an average of 50.Two numbers with an average of 50 is 49 and 51.
50
Seven: 53,59,61,67,71,73,79.
80
prime numbers between 50 and 80 = 53,59,61,67 ,71,73,79
All even numbers between 50 and 80 are composite.
80
463
40:64 = 50:80
50 25,2 5,5,2 62 2,31 80 40,2 20,2,2 10,2,2,2 5,2,2,2,2
L is 50 in roman numbers and in the middle ages R was used for 80. (in old times 80 would be LXXX or XXC)
Seven: 10, 16, 20, 25, 40, 50, 80.
-50