SOLUTION: If a cyclist travel for xkm in 4hour and (x+6o)km in 7 hour if its average speed does not exceed 150km find x

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Question 811922: If a cyclist travel for xkm in 4hour and (x+6o)km in 7 hour if its average speed does not exceed 150km find x
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

the distance he travels is xkm in 4h , which means speed is xkm%2F4h
and %28x%2B60%29km+%2F7h

%28xkm%2F4h%2B+%28x%2B60%29km+%2F7h+%29%2F2...=> average speed
+xkm%2F8h%2B+%28x%2B60%29km+%2F14h
+xkm%2F8h%2B+x%2F14h+%2B60km+%2F14h

%2811x%29km%2F56h+%2B60km+%2F14h+
if its average speed does not exceed 150km+, then
%2811x%29km%2F56h+%2B60km+%2F14h+%3C=150km%2Fh....solve for x, both sides multiply by 56h to eliminate denominator

%2811x%29km56h%2F56h+%2B%2860km%2A56h%29+%2F14h+%3C=%28150km%2A56h%29%2Fh

%2811x%29km++%2B60km%2A4%3C=8400km+
%2811x%29km++%2B240km++%3C=8400km+
%2811x%29km+%3C=8400km+-240km
11xkm+%3C=8160km+
x+%3C=8160km+%2F11km
highlight%28x+%3C=741.81%29+
check:
%2811%2A741.81%29km%2F56h+%2B60km+%2F14h+%3C=150km%2Fh
8160km%2F56h+%2B60km+%2F14h+%3C=150km%2Fh

145.71km%2Fh%2B4.29km%2Fh%3C=150km%2Fh
150km%2Fh%3C=150km%2Fh which is true

take one number less them 741.81

%2811%2A741+%29km%2F56h+%2B60km+%2F14h+%3C=150km%2Fh
8151km%2F56h+%2B60km+%2F14h+%3C=150km%2Fh
145.55km%2Fh%2B4.29km%2Fh%3C=150km%2Fh
149.84km%2Fh%3C=150km%2Fh which is true