Malik earned $2,344.55 fixing computers. He charged $35.50 per hour. Which expression does NOT use appropriate compatible numbers to estimate the total number of hours he worked?
A. 2,400 ÷ 30
B. 2,400 ÷ 40
C. 2,000 ÷ 40
D. 2,000 ÷ 30

Asix-sided die of unknown bias is rolled 20 times, and the number 3 comes up 6 times. in the next three rounds (the die is rolled 20 times in each round), the number 3 comes up 6 times, 5 times, and 7 times. the experimental probability of rolling a 3 is 10 %, which is approximately % more than its theoretical probability. (round off your answers to the nearest integer.)