Ajeweler has 5 rings, each weighing 18 g, made of an alloy of 10% silver and 90% gold. she decides to melt down the rings and add enough silver to reduce the gold content to 75%. how much silver should she add?

Last saturday, the museum box office sold 281 tickets for a total of $3,954. adults ticket cost $15, and students ticket cost $12. how many of each kind of tickets were sold?

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

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