Let Camembert cheese = C
Let Toma cheese = T
Let Brie cheese =B
Therefore, $$\frac{C}{B}=\frac{5}{8\ }=>\frac{5B}{5}=\frac{8C}{5\ }=>\ B=1.6C$$
Question => The price of a kilogram of Toma cheese is how much higher (in dollars) than the price of a kilogram of Camembert cheese?
i.e what is T - C?
Statement 1 => The price of 1 kilogram of Brie cheese is 25% higher than the price of 1 kilogram of Toma cheese
B = T + 25% of T => B = T + 25/100 * T
B = T + 0.25 T => B = 1.25T Since B = 1.6C
1.6C = 1.2ST but the value of C and T are unknown.
Hence, statement 1 is NOT SUFFICIENT

Statement 2 => The price of 1 kilogram of Toma cheese is 28% higher than the price of 1 kilogram of Camembert cheese
T = C + 28% of C => T = 1.28C value of T and C is still unknown. Hence, statement 2 is NOT SUFFICIENT

Combining both statements together
None of the statements gives the exact value of C, T or B.
The information available is not enough to estimate the value of T - C, so, both statements combined are INSUFFICIENT.

The answer, therefore, is option E.