Absolutely. But be prepared for
(a) resentment, or worse, from the other worker
(b) an exit from the job in the near future.
It may not be wise for a firm to employ a worker at $20 per hour when another worker can perform the same job for $10 per hour, as this creates unnecessary labor costs. However, factors such as the experience, qualifications, or productivity of the higher-paid worker may justify the wage difference. Additionally, if the $20 worker brings unique skills or contributes to higher overall efficiency, the investment might be worthwhile. Ultimately, the firm's decision should consider both cost-effectiveness and the value each worker brings to the organization.
By the equilibrium between supply and demand for workers
A company might do this if they value a particular employee a lot. For example, the particular employee might have a lot of experience in the job, be more productive, or commit less errors.
Only if there is some special reason for it: the lower paid one might be an apprentice; the higher paid one may have special skills. There can be many more reasons for it. Perhaps you have read the Bible story about such a matter.
There may be many reasons for it - some good, some bad and some in between: One of them is the owner's relative; The higher paid worker is more skilled (or faster); The two workers may be in different locations - with different employment rates and costs of living (that is the whole point of multinationals sourcing overseas!). The firm may have to justify its decision to anti-discriminatory agencies.
Variable costs will rise.
to the point where MRP=MC
The marginal benefit will be the value added by that one hour of work. Say the worker is an economist and produces $50 worth of service work in that hour for the firm. The marginal benefit would be $50. If the worker is in production and spins $10 worth of thread into fabric the firm can sell for $100, then the value added (and the marginal benefit) is $90.
The price it costs to start a law firm varies. The price can range from 20,000 dollars up to 100,000 dollars.
marginal revenue product
anytime -Of course there is no limit for a comapny to buy another one
I believe in economics we assume that firms are rational and because of this a rational firm would not employ additional labor if it caused a decline in the total output of the firm.