A 34 g glass thermometer reads 21.6°C before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 38.7°C. What was the original temperature of the water?

I need help on this please could someone please help out.Thank you!

2 answers

the sum of heats gained is zero.

massglass*specheatglass*(21.6-38.7)+135*specheatwater*(Ti-38.6)=0

solve for Ti
I got 15.43 degree Celsius but its wrong. I don't know why please help. Thank you!