the half life of radium is 1690 years. if 100 grams are present now, when will there be 20% of the original amount

At the school fair, grade 3 raises 84 more then grade 4. grade 4 raises 112 more then grade 2. grade 3 raises 360. how many dollars does grade.2 have

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg

The avenues in a particular city run north to south and are numbered consecutively with 1st avenue at the western border of the city. the streets in the city run east to west and are numbered consecutively with 1st street at the southern border of the city. for a festival, the city is not allowing cars to park in a rectangular region bordered by 5th avenue to the west. 9th avenue to the east, 4th street to the south, and 6th street to the north. if x is the avenue number and yis the street number, which of the following systems describes the region in which cars are not allowed to park? 5th ave 9th ave