Data Sufficiency

Do more than 50% of the children in a certain group have brown hair?

1) 70 % of the boy in the group have brown hair.
2) 30% of the children in the group are girls with brown hair.

The OA is E

Source: GMAT Prep

swerve wrote:Do more than 50% of the children in a certain group have brown hair?

1) 70 % of the boy in the group have brown hair.
2) 30% of the children in the group are girls with brown hair.

The OA is E

Source: GMAT Prep

From the Question, we do not have information on the total number of children in the group or the numbers of boys or girls in the group.

Let us assume the total no: of boys in the group is B and no: of girls in the group is G. Total number children in the group is X
X = B +G

From (1) , We just know that 70% of boys have brown hair. that is 0.7B = Brow hair. No information on the girls. so this statement is NOT Sufficient.
From (2) We just know that 30% of children in the group have brown hair. 0.3G= brown hair. No information on the Boys. so this statement is NOT Sufficient.

Combining 1 and 2. we know B+G = X , 0.7 B + 0.3 G = ? so we do not know either of X, B or G, we cant solve the equation. so evening combing both 1 and 2 statements, we dont have sufficient information to solve the question.

Answer is E