Jenny can fit 2 cake tins along the shorter side of the oven tray at one time.
To determine how many cake tins can fit on the oven tray, we need to consider the dimensions of both the cake tin and the oven tray.
The cake tin has a diameter of 25 cm, which is equivalent to 250 mm (since 1 cm = 10 mm).
The oven tray has dimensions of 600 mm by 500 mm.
Now, let's calculate how many cake tins can fit along the longer side (600 mm) and along the shorter side (500 mm) of the oven tray.
Along the longer side (600 mm):
Number of cake tins = 600 mm / 250 mm (diameter of one cake tin)
≈ 2.4
Along the shorter side (500 mm):
Number of cake tins = 500 mm / 250 mm (diameter of one cake tin)
= 2
Therefore, Jenny can fit 2 cake tins along the shorter side of the oven tray at one time.