Hey there!
First, to find the cost of one apple, 50 ÷ 25, which equals 2.
At this point, i am not very sure if you meant to say 75 apples, or $75 apples, so I am just going to give both solutions.
If you meant 75 apples: 75 x 2 = $150
If you meant $75 apples: $75 ÷ 2 = 37.5
Since it isn't realistic to buy 37 apples and one half, round it to 37 apples.
Hope this helps!
Have a great day!