An inventor of the chess board suggested a reward of one grain of wheat for first square, 2 grains for the second, 4 grains for the third, and so on, doubling the amount of the grains for subsequent squares. How many grains would have to be given to the inventor ? (There are 64 squares in the chess board).

There are 64 equal squares in the chess board and every Square has area 6.25 cm2. There is a border of width 2 cm at each of its four sides. Find the length of the side of chess board.

If two of the 64 squares are chosen at random on a chess board, the probability that they have a side in common is

A corn cob (see Fig. 13.17), shaped somewhat like a cone, has the radius of its broadest end as 2.1 cm and length (height) as 20 cm. If each 1 cm2 of the surface of the cob carries an average of four grains, find how many grains you would find on the entire cob.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds. Answer the following questions giving reasons: (a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil? (b) What would have been the minimum number of ovules present in the ovary? (c) How many megaspore mother cells were involved? (d) What is the minimum number of microspore mother cells involved in the above case? (e) How many male gametes were involved in this case?

Two godowns A and B have grain capacity of 100 quintals and 50 quintals respectively. They supply to 3 ration shops D, E and F whose requriments are 60,50 and 40 quintals respectively. The cost of transportation per quintals from the godowns to the shops are given in the following table: How would the supplies be transported in order that the transportation cost is minimum. what is the minimum cost?

A bag of grain contains 2.8 m^3 of grain. How many bags are needed to fill a drum of radius 4.2 m and height 5m?

QUESTIONS FROM STATE BOARD EXAMINATIONS: A There are 16 chromosomes in a vegetative cell of pea plant. How many chromosomes will be in the following: (i) Pollen grain (ii) Endosperm (iii) Antipodal (iv) Egg cell