Asubstance decays so that the amount a of the substance left after t years is given by: a = a 0 · (0.75) t , where a 0 is the original amount of the substance. what is the amount of time it takes for there to be one-third of this substance left, rounded to the nearest tenth of a year?

Aconstruction worker has rope 9 m long he needs to cut it in pieces that are each 3 /5 m long how many such pieces can he cut without having any rope leftover?

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

Paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.