Rewrite exercise 1 in chapter 2

[jcsherin]

rescript-tutorial/src/chap_2_functional.res

Lines 34 to 45 in 7485e1f

	-----------------------------------------------------------------------------
	Exercise 1
	-----------------------------------------------------------------------------
	Calculate the discount applicable to shopping cart total amount using the
	following rules:
	1. When the total is either 500 or above:
	- a flat 10% discount.
	2. When the total is either 200 or above, but below 500:
	- add 25 to,
	- a 5% discount on the amount greater than 200
	-----------------------------------------------------------------------------

Rewrite the exercise copy to improve readability & comprehension.

The part where the 5% discount has to be applied has issues. It is easy to miss out on the fact that the calculation involves deducting the cart total amount from 200, before applying a 5% discount.

[ForgottenProgramme]

@jcsherin
Also, what is "add 25 to, " on line 43 suppose to mean?

[Deep-Codes]

@ForgottenProgramme When the value is 200 >= & <500

discount = (value - 200 * 0.05) + 25

So for 499
discount = ( 499 - 200 * 0.05 ) + 25 = 39

[ForgottenProgramme]

2. When the total is either 200 or above, but below 500:
   • add 25 to,
   • a 5% discount on the amount greater than 200

I think, we can change this to:

2. When the total is either 200 or above, but below 500:

• 5% discount on the amount greater than 200, plus 25. That is, discount = (total-200) * 0.05 + 25 .

[jcsherin]

@ForgottenProgramme I've made a draft-PR. Please take a look and see if any other changes are required.

[ForgottenProgramme]

@jcsherin , Okay.