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. Three years from today, the difference between the age of the boy and the combined ages of the girls will be Choose the correct choice from the following choices:	A) 1	B) 2	C) 3	D) –2	E) –1
girl1: g1, girl2: g2, boy:b, these are the symbols for their ages today.   g1+g2&lt;b   (1 year from now): (g1+1)+(g2+1) = b+1 ; g1+g2 = b-1   The difference between the girls's age and the boy's age is one today:   Assume ages, g1:20, g2:25, b:46 (notice the difference is currently 1); in 3 years the ages will be g1:23, g2:28, b:49 ; 49-(23+28) = -2   The Answer should be –2.
<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. Three years from today, the difference between the age of the boy and the combined ages of the girls will be