A can work twice as fast as B. A and C together can work three times as fast as B. if A,B and C complete a job in 30 days working together, in how many days can each of them complete the work.
There are 3 types of shadings in the triangles, 3 types of legs, 3 positions of circles, each of which is used only once in a single row. The circle is shaded in alternate figures.
In each row, the second figure is obtained from the first figure by adding two mutually perpendicular line segments at the centre and the third figure is obtained from the first figure by adding four circles outside the main figure.