Under which of the following conditions is a person most likely to fall sick ?
when she is recovering from malaria.
(ii) when she has recovered from malaria and is taking care of someone suffering from chicken-pox.
(iii) when she is on a four-day fast after recovering from malaria and is taking care of someone suffering from chicken-pox. Why ?

Under which of the following conditions are you most likely to fall sick ? (i) when you are taking examinations, (ii)when you have travelled by bus and train for two days, (iii) when your friend is suffering from measles. Why ?

From the pair of linear equations in the following problems and find their solutions (if they exist) by elimination method : A part of monthly hostel charges in a college are fixed and remaining depend on number of days one has taken food in the mess. When a student A takes food for 20 days, he has to pay rs 1000 as hostel charges whereas student B who takes food for 26 days has to pay rs 1180 as hostel charges. Find fixed charges and cost of food per day.

Juhi wants to buy a bicycle. She goes to the market and finds that the bicycle she likes is available for ₹1800. Juhi has ₹ 600 with her. So, she tells the shopkeeper that she would not be able to buy it. The shopkeeper, after a bit of calculation, makes the following offer. He tells Juhi that she could take the bicycle by making a payment of ₹600 cash down and the remaining money could be made in two monthly instalments of ₹610 each. Juhi has two options one is to go for instalment scheme or to make cash payment by taking loan from a bank which is available at the rale of 10% per annum simple interest. Which option is more economical to her?

By examining the chest X-ray, the probability that TB is detected when is actually suffering from TB is 0.99 the probability of a healthy person diagonosed to have TB is 0.001. In a certain city, 1 in 1000 persons suffer from TB. A person is selected at random and is diagonsed to have TB. What is the probability that he/she actually sufferes from TB?

Light from an ordianry source(say a sodium lamp) is passed through a polaroid sheet P_1 .The transmitted light is then made to pass through a second polaroid sheet P_2 ,which can be rotated so that the angle (theta) betwen the two polaroid sheets varies from 0^@ to 90^@ .Show graphically the variation of he intensity of light transmitted by P_1 and P_2 as a function of the angle theta .Take the incident beam intensity as I_0 . Why does the light from a cleear blue portion of the sky,show a rise and fall on intesnity,when viewed through a polaroid ,which is rotated?

Sangeeta's gardner was suffereing from high blood pressure but he was not caring for his health. One day Sangeeta took him to the doctor. The doctor advised him to take less quantity of salt in his diet. Sangeeta suggested gardner's wife to cook food for her husband with very little salt. Answer the following questions: Why did the doctor advise Sangeeta's gardner to take less quantity of salt?