1.A mathematician was 70 in the year 500 and he was 80 in the year 490.find the year in which he was born
ans :570 b.c
2.There are 100 pieces of zigzags(don t bother of zig zag) which can be combined two at a time dicretely or with with a unit of some zigzag. How many such copmbination are necessary to make asingle whole unit.
ans :99 (Similar to the problem that says: 10 players playng mathes one lose will make them out of tournament)
3.a.) there is a cube which is painted out side ,which is then divided into 125 cubes of equal size.Find the number of cubes which are having color at the 3 faces ,number of cubes having color at 2 faces and also at the one face,also cubes having no color
ans:(3 faces=8
2 faces=36, 1 faces=54 ,no colr=27 )
3.b) if these cubes r placed in the tray and shuffelled then brougt into stationary state the find the probality that the red face is pointing above
ans: 1/5 or 0.2.
4.) There are 729 balls of equal size and shape out of which one is heavier than rest all.Find the minimum number of weighing tha are required to find out that faulty ball
ans (12).