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?
Choose the correct option.
A) 14(2/7) B) 16(2/3) C) 10 D) 8 E) 13(3/7)
The salary of Richard as a percentage of his family's total income was 20%   The salary of Richard as a percentage of his family's total income now is 30%   The percentage points that have increased is 10 (from 20% to 30%).   Answer (10)
<result>C</result>
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?