Instead of solving two equations together, we can test each answer choice directly against both conditions in the question, since only one value of the original mangoes in basket A can satisfy both conditions at once.
Only a = 100 satisfies both conditions together, so the original number of mangoes in basket A must be 100.
Let's summarize:
So the original number of mangoes in basket A is 100, the same answer reached earlier by solving two equations, this time found by checking each option.