Students in a music program gradually increase the amount of time they practice. The first week, they practiced 20 minutes per day. Each week thereafter, they increased their practice time by 50% until they practiced an hour per day. In what week of the program did the students begin practicing an hour per day? *

a. week 5
b. week 4
c. week 3
d. week 2

Zed is making a centerpiece for his dining room table by putting sand in a cube-shaped vase. the vase is 0.25 meters in length, width, and height. he bought 25 kg of sand. assume the density of dry sand is 1,602 kgm3. what is the volume of the sand that zed purchased? the volume of the sand is approximately m3. enter your answer as the number that correctly fills in the blank in the previous sentence. if necessary, round your answer to six decimal places, like so: 42.536475