Answer: D
Given:
G1+G2+G3+B(Tall)+B(Short)= 600
B(Tall)= 120 that means G1+G2+G3+B(S)= 460
What we have to find is (G1+G2+G3)/3< 117 (Yes or No)
Statement A
B(S)= 130
This gives us the age of both boys and we can find the sum of the ages of all the three girls. We will divide the sum by 3 and that will give us the average height of the girls. Hence sufficient for us to answer the question
Statement 2
Shortest members of the group are the two girls and they both have the same height which is 110
G1 (shortest) + G2(other shortest) + G3 + B(Tallest) + B(Short)= 600
110+110+ G3+140+ B(S)=600
G3+B(S)= 240
we know that each G3 & B(S) have a height above 110. Therefore we can take two cases.
Case-I= G(3) has a height of 129 and B(S) has a height of 111
(G1+G2+G3)/3= (110+110+129)/3 = 116.3.. which is less than 117
Case-I= G(3) has a height of 111 and B(S) has a height of 129
(G1+G2+G3)/3= (110+110+111)/3 = 110.3.. which is also less than 117
Hence statement two is sufficient to answer the question. Therefore the answer is D (each statement alone is sufficient)