Answer No. 3 Only! Sub: Differential Equation MUST BE CLEAR SOLUTIONS

Inthcrt'ons: Solve the following problem neatly,r and completely. Create a table representing the given data. Box your nal answers. Answersi'Solutions must be handwritten in a bond paper. 3. A glass of hot milk at 100C is brought in a room where the temperature is maintained at 20C. After 15 minutes, the temperature goes down to 90C. Find the a) temperature of the glass of milk after 15 more minutes b) time it takes until the temperature goes down to 3T\"C. 4. Radium decomposes approximately at a rate proportional to the amount present. If it is 100 grams now, and it will be 96 grams a hundred years later, nd a} the half-life of the radium b} the time it takes for 2E3 of its amount to be decomposed. 5. For a substance C, the time rate of conversion is proportional to the square of the amount it of unconverted substance. Let k be the numerical value of the constant of proportionality and let the amount of the unconverted substance be x0 at time t = 0. Determine x for all t 2 0