Roberto has three children: two girls and a boy. All were born on the same date in different years. The sum of the ages of the two girls today is smaller than the age of the boy today, but a year from now the sum of the ages of the girls will equal the age of the boy. four years from today, the difference between the age of the boy and the combined ages of the girls will be  Pick:
A) 1	B) 2	C) 3	D) –3	E) –1
Approach I (Plugin's)   Girl I ............... Girl II ................ Boy   1 ....................... 1 ........................ 3 (Assume the current ages)   1 + 1 &lt; 3 .......... (Satisfies the given condition)   1 Year later there ages are   2 ....................... 2 ......................... 4   2 + 2= 
<gadget id="calculator">2 + 2</gadget>
<output>4</output>
4 ............ (Satisfies the given condition)   After 4 years there ages are   5 ....................... 5 ............................ 7   –3ifference= 7 - (5+5) = 7 - 10 = -3   Answer = –3
<result>D</result>
Roberto has three children: two girls and a boy. All were born on the same date in different years. The sum of the ages of the two girls today is smaller than the age of the boy today, but a year from now the sum of the ages of the girls will equal the age of the boy. four years from today, the difference between the age of the boy and the combined ages of the girls will be