Initially there are twice as many adults as children on the bus. At the next stop, 12 more people board the bus. There are 1.5 times as many children as before and 1.75 times as many adults as before. How many adults are there on the bus now?
Let's assume the initial number of children on the bus is x.
The initial number of adults on the bus is 2x.
After the next stop, 12 more people board the bus.
So the total number of children on the bus is now 1.5 * x = 1.5x
The total number of adults on the bus is now 1.75 * 2x = 3.5x
The total number of people on the bus now is 1.5x + 3.5x + 12 = 5x + 12
Since the total number of people on the bus is constant, we can set the initial number of people equal to the current number of people on the bus: 2x + x = 5x + 12
Combining like terms, we get 3x = 12
Dividing both sides by 3, we get x = 4
So the initial number of adults on the bus was 2 * 4 = <<2*4=8>>8.
And the current number of adults on the bus is now 3.5 * 4 = <<3.5*4=14>>14. Answer: \boxed{14}.