Question 87
Solve the following:
Find a number whose fifth part increased by 30 is equal to its fourth part decreased by 30.
Let the number be x.
According to the question,
x5+30=x4−30
⇒x5−x4=−30−30⇒4x−5x20=−60⇒−x=−60×20∴x=1200
Hence, the required number is 1200.