Chetan and his 5 siblings buy a present for their mother on Mother's Day. As the eldest brother, he pays 0.2 of the cost of the present. The rest of the siblings share the balance equally. Each sibling pays $9.50 less than Chetan. What is the cost of the present.

Let's say that X is what the other 5 siblings pay. X + $9.50 is what Chetan pays. X + $9.50 is 1/5 of the cost of the present. To solve this we have to do 0.8 divided by 5 (the remaining cost split between 5 people) which is 0.16. Now from this we can learn that $9.50 is 0.04 of the cost of the present. A simple way to solve this is do 1.00 divided by 0.04 and then multiply $9.50 by that amount. 1.00 divided by 0.04 is 25 so $9.50 times 25 is $237.5.

The present costs $237.5

As I read over this I may not be correct, however this is how I solved it as an advanced mathematics grade 8 student.