4x - 1 < 11
Add 1 to both sides
4x < 12
Divide both sides by 4
x < 3
x is less than 3
<span>Chris' average speed is 3.5mph:
Lets take Chris' brother speed = B
then Chris speed = (B+ 1) mph-------given in the question
and:
The average speed for covering 18 miles= chris' average speed + his brother's
average speed = (B+ 1) + B
since Speed = Distance covered / time taken
then average speed for 18 miles can also be found by: 18 miles/3 hours = 6 miles per hour
then we have; (B+ 1) + B = 6mph
(B +1) = (6-B)
B+B = 6-1=5
2B=5
B=5/2=2.5 mph (this is Chris' brother average speed)
Hence Chris' average speed is = B+1= 2.5+1= 3.5mph</span>
Answer:
Step-by-step explanation:
Well we can find how far he travels in 55 seconds if he swims at constant speed of 5/3 meters.
5/3 times 55 = approx. 91.66 meters
Therefore Xavier will not quality for the national Swim Meet because he didn't swim 100 meters in 55 seconds
