To determine the new product mix and total contribution, we need to consider the existing limiting factors and the demand for each product.

Given:

Contribution per unit for Product A: R$1\mathrm{.}50$

Contribution per unit for Product B: R$1\mathrm{.}00$

Demand for Product A: $200$ units

Demand for Product B: $150$ units

To find the new product mix, we need to allocate the available resources based on the contribution per unit. Since the contribution per unit for Product A is higher, we should prioritize producing more units of Product A$.$

Let's assume the available resources are sufficient to meet the demand for both products. In that case, we can allocate the resources as follows:

Calculate the total contribution for each product:

Total contribution for Product A: R$1\mathrm{.}50*200$ units $=$ R$300$

Total contribution for Product B: R$1\mathrm{.}00*150$ units $=$ R$150$

Calculate the contribution ratio for each product:

Contribution ratio for Product A: R$300/($R$300+$ R$150)=0\mathrm{.}67$

Contribution ratio for Product B: R$150/($R$300+$ R$150)=0\mathrm{.}33$

Determine the new product mix:

New units of Product A: $0\mathrm{.}67*(200+150)=201$ units

New units of Product B: $0\mathrm{.}33*(200+150)=99$ units

Therefore, the new product mix is $201$ units of Product A and $99$ units of Product B$.$

The total contribution for the new product mix is R$300($R$1\mathrm{.}50*201$ units$)$ for Product A and R$99($R$1\mathrm{.}00*99$ units$)$ for Product B$,$ resulting in a total contribution of R$399.$

Please note that if the available resources are not sufficient to meet the demand for both products, the product mix and total contribution may vary.