Three planks of different lengths, U, V and W are nailed together to make a frame as shown. Plank U has 3 holes which divide it into 4 equal parts. Plank V has 4 holes which divide it into 5 equal parts and Plank W has 5 holes which divide it into 6 equal parts. In the frame, the holes S, T and U are three corners of an equilateral triangle. Plank U is 192 cm long. What is the total length of Plank U, Plank V and Plank W?
Length of Plank U = 192 cm

Length of each interval of Plank U
= 192 ÷ 4
= 48 cm

Length of 2 intervals of Plank U
= 2 x 48
= 96 cm

Length of each interval of Plank V 
= 96 ÷ 3
= 32 cm

Length of Plank V
= 5 x 32
= 160 cm

Length of each interval of Plank W
= 96 ÷ 4
= 24 cm

Length of Plank W
= 6 x 24
= 144 cm

Total length of Plank U, Plank V and Plank W
= 192 + 160 + 144
= 496 cm

Answer(s): 496 cm