If the price of a gallon of milk and a loaf of bread both increased by

Statement 1:
Price of the basket is $3.60. All you can do from here is calculate the price for the year 1990 for the TOTAL BASKET. 1.1*3.6 = 3.96. The statement does not give you any information about the single components. Insufficient.

Statement 2:
All you can do with this is calculate backwards 3.96/1.1 = 3.60 for the Total Basket. Insufficient.

Since Statement 2 does not add new information to Statement 1, Answer E.

Statement 1 :
M + B = 3.60

Two unknown one equation hence Not sufficient to find B

Statement 2 :
1.1 M + 1.1B = 3.96
M + B = 3.60

Two unknown one equation hence Not sufficient to find B

Combining statement 1 and 2 we get only one equation , hence Not sufficient -- Option E

This is very typical Gmat Type DS, where combining statements present 2 equation to solve two unknown . However in reality it is just one equation and 2 unknown.

GHOST EQUATION -

You mean answer choice E not option A right?

Let, Price of Milk in 1987 = M
and Price of Bread in 1987 = B

i.e. Price of Milk in 1990 = 1.1M
and Price of Bread in 1990 = 1.1B

Questions : M = ?

Statement 1: Together, a loaf of bread and a gallon of milk cost $3.60 in 1987.
M+B = $3.6
One Equation and Two variables will give Infinite many solutions for M and B so
NOT SUFFICIENT

Statement 2: Together, a loaf of bread and a gallon of milk cost $3.96 in 1990.
1.1M+1.1B = $3.96
i.e. M+B = $3.6
One Equation and Two variables will give Infinite many solutions for M and B so
NOT SUFFICIENT

Combining the Two statements
Since both statements are leading to the same equation so combining them doesn't solve the purpose either. Hence,
NOT SUFFICIENT

Answer: Option E

reto .. thanks for correcting. Yes it is Option E

Solution:

We can let the price of a gallon of milk and a loaf of bread in 1987 be m and b, respectively. Thus their prices were 1.1m and 1.1b in 1990, respectively. We are looking for the value of b.

Statement One Only:

Together, a loaf of bread and a gallon of milk cost $3.60 in 1987.

This means b + m = 3.60. Since we have one equation with two unknowns. Statement one alone is not sufficient.

Statement Two Only:

Together, a loaf of bread and a gallon of milk cost $3.96 in 1990.

This means 1.1b + 1.1m = 3.96. Since we have one equation with two unknowns. Statement two alone is not sufficient.

Statements One and Two Together:

Using the two statements, we have two equations:

b + m = 3.60 and 1.1b + 1.1m = 3.96

It seems we have enough information to solve for b. However, upon a closer look, if we divide 1.1b + 1.1m = 3.96 by 1.1, we have b + m = 3.60, which is exactly the same as the first equation. That is, the second equation doesn’t give us any more information than the first. Therefore, we still can’t determine the value of b.

Answer: E

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