For a question like this, all you have to do is remember that a percentage is simply a fraction expressed as a decimal. So, all we have to do is:

, and then multiply our decimal answer by 100 to get the percentage:

= 0.34
0.34 x 100 = 34
Therefore 34% of the students walk to school.
I hope this helped and remember to please try and understand the maths that got the answer, not just writing the answer down :))
Answer:
14000
Explaination:
spwithvat = sp without vat + 13% of sp without vat
let, sp without vat be x.
sp with vat= x + 13% of x.
or, 13447 = x + 13/100 × x
or, 1344700 = 113x
or, x= 1344700/113
x = 11900
Let, mp be y.
sp with vat = mp - 15% of mp
or, 11900 = y - 15/100 × y
or, 1190000 = 85y
or, y= 1190000/85
y= 14000
I think its b , but iam not sure
21 is the opposite of -21