Question 40
Choose the option which has the same relationship with the number as displayed by the first pair.
648 : 20: :16:?
Solution
648
Sum of digits is 18. Product of digits is 192. These two is not describing the relation. Let's try number of factors.
648 = $$2^3*3^4$$
Number of factors = 4*5 = 20
This is correct.
Number of factors for 16 = 5.
