Q: Kenneth spent 10% of this earnings this week on a new joystick. If he is left with $405, how much were his earnings?
user


A: Since Kenneth spent 10%, then he is left with 100% - 10% = 90% of his earnings.
Since 90% of his earnings is worth $405, then 1% of his earnings is $405/90 = $<<405/90=4.50>>4.50.
Hence, Kenneth's earnings is $4.50 x 100 = $<<450=450>>450. The answer is  450.
assistant