7. The weight of a radioactive chemical decreases by 50% every 1,600 years. If its original weight is 4 kg ,what will its weight be after 19,200 years?(give the ans correct to the nearest g.)ANS : 1g 18.The following table shows the values of a flat in 2003 and 2004. YearValue2003$8,340,0002004$8,737,000 Suppose the value of this flat increases at a constant rate year, and the growth factor of k.(a) find the value of k.ANS : 1.05 (b) Find the value of the flat in the following years :(i) 2002 (ii) 2006(give the ans correct to 3 sig.fig.) (i) ans : $7 960 000 (ii) ans : $9 590 000 20.The monthly savings of a family decreased at a rate of 10% per month from May this years. If the total savings of the family for May ,June and July were $40650 ,what were the monthly savings of the family in May?ANS : $15 000 *睇唔明英文版,可問我拎中文版! 求step,thx~~
一定要有完整啲step~~唔好亂做,要同個ans一樣,一定要岩同埋要清楚(要睇得明你寫咩)!!!!thx~~~