A centigrade and a Fehrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fehrenheit thermometer registers `140^(@)F` . What is the fall in temperature as register by the centigrade thermometer

Options

A. 30°
B. 40°
C. 60°
D. 80°

Answer

B

Explanation

`(Delta T_C)/(100) = (Delta T_F)/(180)`
`rArr Delta T_(c) = 100 xx (72)/(180) = 40^@ C`
Fall in temperature `= 40^(@)C`.