Ekta earns ₹3000 in 10 days. How much will she earn in 30 days ?

Activity of a certain radioactive sample is 25 muCi at the end of 20 days and 6.25 mu Ci at the end of 40 days. What will be its activity at the end of 30 days?

Shaina pays ₹15000 as rent for 3 monts. How much does she has to pay for a whole year, if the rent per month remains same?

Biogas contains 70% methane. The calorific value of methane is 55 kJ/kg. If a family requires 10,000 kJ of energy per day, how much biogas is needed per day?

A certain radioactive substance has half life period of 10 days. How long will it take for its activity to reduce to 1/8 of its original value ?

A contract on construction job specific a penalty for delay of completion beyond a certain date as follows : Rs. 200 for the first day, Rs.250 for the second day, Rs. 300 for the third day, etc., the penalty for each succeeding day being Rs. 50 more than for the preceding day. How much money the contractor has to pay as penalty, if he has delayed the work by 30 days ?

A contract on construction job specifies a penalty for delay of completionbeyond a certain data as follows: Rs 200 for the first day , Rs250 for the second day, Rs 300 for the third day , etc., the penalty for each succeeding day being Rs50 more than for the preceding day . How much money the contractor has to pay as penalty , if he has delayed the work by 30 days ?

One gram of a radioactive element reduces to 200 mg in 10 days. Then the mass of the sample at the end of another 10 days is (in mg)

Lipika reads a book for 1frac{3}{4} hours everyday. She reads the entire book in 6 days. How many hours in all were required by her to read the book?