उत्तर :
व्याख्या :

You have to actually count all the balls in the pyramid.Simple way is to count the balls in each level. So lower most level lets say 1st level has 4 x 4 balls; i.e. 16 ballsSimilarly 2nd level has 3 x 3 balls; i.e. 9 balls.3rd level has 2 x 2 balls; i.e. 4 balls.The top most level has just 1 ball. So the total number of balls is 16+9+4+1 = 30.   So the image has 30 Balls in all.