Richard receives an increment in his salary. His salary presently forms 30% of the total income of his family. Before the increment his salary used to form 20% of the total income of his family. By how many percentage points did the salary of Richard as a percentage of his family's total income increase?
A) 14(2/7)
B) 16(2/3)
C) 10
D) 8
E) 13(3/7)
A) 14(2/7)
B) 16(2/3)
C) 10
D) 8
E) 13(3/7)