a trader buys n oranges at the rate of 5 oranges for$90 eight of the oranges are bad. so she sells the rest at 4 oranges for $120 and makes a profit of $900 find n?

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g