Voltage drop...

If three resistors are connected in series and we have 10 volts drop across resistor one and further 15 volts drop across resistor three.
What is the voltage drop across resistor two if the supply voltage is 50 volts ???

For me it's not enough information but if you think you have the answer please fill welcome.

It's really EXTREMELY basic maths:

10+15+x=50

Change it round to find x!.

What was I thinking .........

Thanks.