Hi

(1)

a customer, who buys two loaves, pays p + q
average price per loaf is (p + q)/2
it is 10 percent less than the price of single loaf p

so (p + q)/2 = 0.9p
p + q = 1.8p
q = 0.8p

it is INSUFFICIENT

(2)

total price X = 10
amount of loaves n = 6
X = p + q(n - 1)
10 = p + 5q
[spoiler]
it is INSUFFICIENT[/spoiler]

but

q = 0.8p
10 = p + 5q

10 = p + 5*0.8p
p = 2
q = 1.6
[spoiler]
both statements 1 and 2 are together SUFFICIENT - answer C[/spoiler]

hope it helps!

I actually set my equation up a bit differently --

Question stem: 1(P) + (x-1) Q = total cost
Where P is price for first loaf , Q is price for additional loaves and x = total loaves.

Stmt 1
x=2. so 1(P)+1(Q) = .90(P) , since the price for 2 is 10% less than than the price of 2.

insuff. ## pls explain whats wrong with my algebra here...even though i got it right, why do you divide by 2? ##

Stmt 2
x=6. so 1(P) + 5(Q) = $10.00 insuff. alone

Together -
two linear equations, can solve for q and substitute... I got C but not sure whats up with my equations.