Answer:
0.6 m
Step-by-step explanation:
We can solve the problem by using the lens equation:
![(1)/(f)=(1)/(p)+(1)/(q)](https://img.qammunity.org/2020/formulas/physics/high-school/n7woqmvve1hantxzvmg5itsbubgjrzuc3a.png)
where
f is the focal length
p is the distance between the lens and the candle
q is the distance between the image and the lens
In this problem, we have
p = 1.2 m is the distance of the candle from the lens
f = 0.4 m is the focal length
Solving the equation for q, we find
![(1)/(q)=(1)/(f)-(1)/(p)=(1)/(0.4 m)-(1)/(1.2 m)=1.67 m^(-1)\\q=(1)/(1.67 m^(-1))=0.6 m](https://img.qammunity.org/2020/formulas/physics/middle-school/p022j0m6uu2t2dmtn50tfab8ysf2q0zznb.png)