The steam point and the ice point of a mercury thermometer are marked as `80^@ and 10^@`. At what temperature on centigrade scale the reading of this thermometer will be `59^@` ?

Explanation

Let the relation between the thermometer reading and centigrade by `ax + b`
(x represents `""^(@)C` and y respresents temperature in new scale)
Given at `x=100,y=80"and at" x=Qy=10`
`therefore" " 80=100a+b,implies a=0.7`
Now, we have to find x when `y= 59`
`therefore" "59=0.7x+b impliesx=70`
`therefore` THE Answer is `70^(@)C.`