What is the sum of the total surface areas of all the cubes formed when a cuboid of size  5.2 m x 13 m x 39 m is cut completely into the least possible number of cubes, all of which are identical?

In the graph alongside, the four labelled points are A(5, 0), B(7, 0), C (7, 9) and D(5, 4). Which of the following is closest to the area of the shaded region?

ABCD is a rhombus with O as its centre. P, Q and R are three ants travelling from A to C along the paths AOC, ADC and ABOC respectively. All the three ants leave A at the same time and reach C simultaneously. The ratio of the speeds of P and R is 2 : 3. If all the three ants travelled along the path ADOC, what will be the ratio of their travelling times