First look at the watch
$x = 25 + \dfrac{y}{12}$
$x - \frac{1}{12}y = 25$ ← Equation (1)
Second look at the watch
$y = 15 + \dfrac{x}{12}$
$-\frac{1}{12}x + y = 15$ ← Equation (2)
From Equations (1) and (2)
$x = 26.43$
$y = 17.20$
Time in the 2nd case = 5:17.20 ← answer