Answer :
Yes, because you can check the math. 40% divided by 4 is 10%. Meaning 18 divided by 4 is how much 10% is. 18 divided by 4 is 4.5. 4.5 multiplied by 4 is 40%. 4 times 4 is 16. 4 times .5 is 2. 16 plus 2 equals 18. Therefore, he is correct.