Grade 9 Computer science practice

What is on the worksheet

1. Using zero-based indexing, what is values[2] for values = [36, 84, 26, 4, 93]?

2. A file shrinks from 80 KB to 28 KB. What percentage of its original size was saved?

3. Using zero-based indexing, what is values[4] for values = [27, 36, 90, 82, 51]?

4. Which is a useful debugging record?

   1. Only the output's color.
   2. Only a guess that the computer is upset.
   3. Values and decisions at each relevant step.

5. A file shrinks from 980 KB to 245 KB. What percentage of its original size was saved?

6. How many bits are in 2234 bytes?

7. An outer loop runs 13 times. Each time, an inner loop prints once on each of 15 iterations. How many prints occur?

8. Using zero-based indexing, what is values[1] for values = [36, 39, 8, 50, 98]?

9. An image is 180 pixels wide and 170 pixels high. How many pixels does it contain?

10. An image is 220 pixels wide and 100 pixels high. How many pixels does it contain?

11. An image is 130 pixels wide and 150 pixels high. How many pixels does it contain?

12. Start with total = 76. Repeat 7 times: add 7 to total. What is the final total?

13. A 248 MB payload is sent over a constant 15 Mbps link. Use decimal MB and ignore overhead. Find transfer time. Round the final result to 4 decimal places if needed. Answer in s.

14. Convert the binary number 1011111000 to decimal.

15. Convert the binary number 100111010 to decimal.

16. Using zero-based indexing, what is values[3] for values = [40, 20, 88, 64, 23]?

17. FOR i FROM 5 TO 213 INCLUSIVE STEP 8: print i. How many numbers are printed?

18. An outer loop runs 3 times. Each time, an inner loop prints once on each of 23 iterations. How many prints occur?

19. A 548 MB payload is sent over a constant 50 Mbps link. Use decimal MB and ignore overhead. Find transfer time. Round the final result to 4 decimal places if needed. Answer in s.

20. Using zero-based indexing, what is values[4] for values = [83, 62, 22, 50, 35]?