A tap supplies water at 25oC while another supplies water at 75oC. If a man wishes to bathe with water at 40oC, the ratio of the mass of cold water to the mass of hot water required is
- 1 : 3
- 15 : 8
-
7 : 3
- 3 : 1
The correct answer is: C
Explanation
Heat lost = heat gainedmh x c x (75 - 40) = mc x c x (40 - 25)
\(\frac{m_h}{m_c}\) = \(\frac{35}{15}\)
= \(\frac{7}{3}\)