can anyone please tell me the formula to work out a percentage?

Question

for example : you have saved £500 for one year. how much interest will you get if the rate is 3.5%? (hint: find 3.5% of £500)

Answer 1

Multiply 500 by 3.5 then, divide the answer by 100 and the answer is £17.50!!

Answer 2

With a calculator:

500 x 0.035 = £17.5

Without a calculator:

500/100 = 5 = 1%
5 x 3 = 15 = 3%
1%/2 = 5/2 = 2.5 =0.5%

3.5% = 3% + 0.5% = 15 + 2.5 = £17.5

Answer 3

George P has a good point.

The simplest way to work out a percentage is :

A % is of 100. 3.5% of 100 = 3.5
3.5% of 200 = 7 (That is double)
3.5% of 300 = 10.5
3.5% of 400 = 14
3.5% 0f 500 = 17.5 (That is 5 times 3.5)

Answer 4

simple interest (SI)=P*T*R/100
[P, principal=£500
T, time=1year
R, rate=3.5% per year]

its given 3.5% of £500
therefore, P*T*R/100 = 3.5/100 * 500
100 and 500 will get cancel , then the remainder is
3.5 * 5
this gives the answer as £17.5 (your answer ,the interest is £17.5)
then to get the total money we should add the interest to the money you save ( P = £500)
hence the monry u get is £517.5

Answer 5

DIVIDE the main figure by 100, then multiply the result by the figure you require add to main figure
£500 d-; 100= 5 x 3.5 = 17.5 result =£517.5

Answer 6

£500 X 3.5 / 100 = £17.50

Answer 7

Let the principal be X:

the formula is X times 3.5/100 = 3.5X/100.

George P. doesn't have a point, his quibble is with the example not with the question thus it is a specious point with no merit.

Answer 8

move the decimal two places to the left.

3.5 = 0.035

then multiply 500 by 0.035

500 x 0.035 = 17.5

3.5% of 500 is 17.5

Another example:

What is 40% of 350?

move decimal to left

thus,

40 = .40

then, multiply it to the number.

350 x .4 = 140

40% of 350 is 140

Answer 9

A = P(1+r)^t
A=500(1.035)^1
A=517.5

I=A - P
I=517.5 - 500
I=17.5

or

I=P(%/100)
I=500(3.5/100)
I=500(0.035)
I=17.5

Answer 10

multiply 500 by 3.5, divide answer by 100
£17.50