Thermometer Y shows a temperature of 24 °Y.
To help us work through this problem, I adapted an image of two common thermometer scales.
Ignore the markings on the thermometers and look at the markings outside them.
(Adapted from www.tf.uni-kiel.de)
On Thermometer X,
On Thermometer Y,
A temperature of 100 °X is 80 X° above the freezing point of water.
The temperature is 64 Y° above the freezing point of water.
∴ On Thermometer Y,