Answer:
A. Ruben's height- 64.8 inches
B. John's height- 3/4 of Josh's height
Explanation:
A. Since Ruben's height is 9/10ths of Josh's, and Josh's is 72 inches, we can find 90% of Josh's height which is 72, therefore giving us 64.8 inches.
B. Now take John's height of being 11/12th as being tall as Ruben, we can enter 11/12th of 64.8 which would give us about 54 inches. Finally, taking John's height of 54 inches, we would divide it with Josh's height of 72 inches. Hence, 54/72=3/4 as a fraction.