Helen runs the longest distance in 4 days.
Helen (In 4 days): 2.75 x 4 = 11
Bill (In 4 days): 10
11 (Helen) > 10 (Bill), so therefore Helen runs the longest distance in 4 days.
Last one is your answer.
X cannot be repeated, but y can
1. 1,2,3,6
2. 1,3,9
3. 1,2,5,10
4. 1,2,3,4,6,12
5. 1,3,7,21
6. 1,2,3,6,9,18
7. 8,16
8. 1,5,25
9. 1,31
10. 3x3
11. 5x5
12. 2x2x2
13. 14 is a composite number
14. 2x2x2
15. 3x5
16. 5 is a prime number
17. 20 is a composite number
18. 2x13
Percent decrease. 41%
percent change= (new-old)/old *100
= -41 % the negative means decreasing
Standard form of given question :8.5016012×10^7