1. You begin 100m from home. If you are running towards home at 9 m/s, how long does it take you to get there?

I guess you can round it to 11 seconds.

Explanation:

Going with a speed 9m/s means you are going 9 meters in each second.

If you are going 9 meters in second how many seconds will it take to 100 meters?

Visually;

9 meters - - - 1 second

100 meters - - - ?seconds.

When you write like this 9 times ?seconds equal to 100 meters time 1 second. (you probably know this but just in case)

So to find ?second you multiply 100meters by 1 and divide it by 9 whixh will give you 11.1111 seconds whixh again I believe you can round it to 11.

(Kind of a) Proof;

If 9m * ?sec = 100 m * 1 sec

you send 9 meters to other side.

?sec = (100 m * 1 sec) ÷ 9m

Hope it was clear and it helps! Please let me know if you have any questions.

a and c

c is 100% but i am confused in a