Answer:
Amanda has 112 stamps
proof:
Lyle has 168 stamps
Shaq has 84 stamps
Explanation:
S = number of stamps Shaquille has
L = number Lyle has
A = number Amanda has
S = 1/2L
A = 2/3L
S + L + A = 364
substituting for S and A
1/2L + L + 2/3L = 364
reduce
2 1/6L = 364
divide both sides by 2 1/6
L = 168
S = 1/2(168) = 84
A = 2/3(168) = 112