The distance between L.F.P and U.F.P in a thermometer is 100 cm. At a certain temperature the mercury thread is 15.5 cm tall, temperature on Fahrenheit scale is      

$$\begin{gathered} New thermometer Fahrenheit thermometer \\ U.F.P-L.F.P=100cm U.F.P-L.F.P=180 cm \\ R-15.5cm F=? \\ \frac{15.5-0}{100}=\frac{F-32}{180} \\ \frac{15.5}{10}=\frac{F-32}{180} \\ \frac{15.5}{10}\times 18=F-32 \\ 27.9+32=F \\ F=59.9^{0}F \end{gathered}$$