Mart owns a trade store and buys wheat flour and rice that she can buy for $10 000. If the price of rice is $2500 per tonne, what is the price of wheat flour per tonne?

Let x be the price of wheat flour per tonne.

Since Mart buys both wheat flour and rice for $10,000, we can write the equation:

x + 2500 = 10000

Subtracting 2500 from both sides, we get:

x = 10000 - 2500
x = 7500

Therefore, the price of wheat flour per tonne is $7500.

Let x be the price of wheat flour per tonne.
Mart can buy y tonnes of rice and z tonnes of wheat flour such that:
2500y + xz = 10000 ....(i)

Given that y + z = 4, substituting this in (i) we get:
2500(4 - z) + xz = 10000
10000 - 2500z + xz = 10000
xz = 2500z
x = 2500

Therefore, the price of wheat flour per tonne is $2500.