Cost of fencing a rectangular field is Rs, 1200. If the cost per m is Rs. 10, find the perimeter of the specific field. Please show working too.

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Heather is a cashier. she can ring up 1212 customers in 99 minutes. at this rate, how many minutes does it take her to ring up 44 customers?

Vinny is interviewing for a job. he wants his take home pay to be at least $42,000.what is the least salary he can earn if he pays 25% income tax?