That's the problem with this kind of question. They expect it to have one correct answer, but there are in fact several. Chances are, the expected answer is 58. One could argue though that - having two interesting distinctions - the number five belongs even less than 58 with it's single distinction.
5 because it is the only single digit number
It is: 35-20 = 15
A factor of a number is any number which the original number can divide into evenly. That is to say, can divide into without leaving a remainder, decimal or fraction. The factors of 15 are: 1, 3, 5 and 15 The factors of 20 are: 1, 2, 4, 5, 10 and 20. The factors of 35 are: 1, 5, 7 and 35.
15
35
35-15 = 20
20 - 35 = -15If you take 35% off 20, you get 13.35 off of 20 is 20 - 35 = -15.
Chlorine-35 (CI-35) has 18 neutrons. It is determined by subtracting the atomic number (17) from the atomic mass number (35).
20-35=15. So 15% increase.
20
15
The least common multiple of 15 , 20 , 35 = 420