I have a big Chocolate. Out of its 8 pieces, I gave 3 pieces to my younger sister, 2 pieces to my brother and rest ate myself, Let’s And what parts to chocolate we individually ate.

I have got soem apples. I gave frac(2)(3)rd of my apples to my brother. I am now left with apples. Let me calculate how.

Grandmother prepared coconut sweets today. She gave my brother 2 more sweets than she gave me and my sister got 3 less than me. Let us form a relation to find how many sweets my brother and sister got in terms of the unknown number of sweets I got.

(1) I have taken measurement of the floor of my living room, I see that the rectangular shaped floor is of 8 m length and 5 m breadth. Let’s find the ratio of its length to it breadth. Let’s also write if the ratio is ratio of grater or lesser inequality.

I have Rs. 150. With 0.3 part of my money I bought exercise books and with 0.4 part I bought a story book. Let me find, what amount of money is left with me.

In the atmosphere, carbon dioxide is found in two forms, i.e., ^12CO_2 and ^14CO_2 . Plants absord CO_2 during photosynthesis in presence of chlorophyll, plants systhesise glucose 6CO_2 +6 H_2O rarr C_6H_12O_6 + 6O_2uarr Half life of ^14CO_2 is 5760 years. The analysis of wooden artifacts for ^14C and ^12C gives useful information for determination of its age. All living organisms, because of their constant exchange of Carbon dioxide with the surroundings have the same ratio of C-14 to C-12, i.e. 1.3xx10^-12 . When an organism dies, the C-14 in it keeps on decaying as follows: 6^14Crarr7^14N+(-1)^0e +Energy Thus, the ratio of C-14 and C-12 decreases with the passage of time. We can measure the proportion of C-14 in the remains of dead organism and determine how long ago it died. The method of carbon dating can be used to date anything made or organic matter, e.g., bone, skeleton, wood, etc. Using carbon dating, materials have been dated to about 50,000 years with accuracy. A piece of wood from an archeological source shows a C-14 activity which is 60% of the activity found in fresh wood today. The age of archeological sample will be: