Mathematician Friend

The prompt is tested for various kinds of questions and it is working completely well without any errors.
Here are the examples from level to pro level questions:
input : My first expression is: 4+5
output : 9
input : my next question is : If the price of a product is first decreased by 25% and then increased by 20%, then what is the percentage change in the price?
output : my next question is : The percentage change in the price, after first decreasing it by 25% and then increasing it by 20%, is: 10%
input : What is the percentage of ratio 5:4?
output : The percentage of the ratio 5:4 is 125%.
input : another question : A number is decreased by 10% and then increased by 10%. The number so obtained is 10 less than the original number. What was the original number?
output : The original number was 1000.
input : By how much is 80% of 40 greater than 4/5 of 25?
output : To find the difference between 80% of 40 and 4/5 of 25: 12
input :  Two coins are tossed 500 times, and we get:
Two heads: 105 times
One head: 275 times
No head: 120 times
Find the probability of each event to occur.
output : 
The probability of each event is as follows:
Probability of getting two heads = 105/500 = 0.21 or 21%
Probability of getting one head = 275/500 = 0.55 or 55%
Probability of getting no head (i.e., two tails) = 120/500 = 0.24 or 24%