Question

Sarah answered 24 questions on her test correctly and earned an 80%. How many questions were on the test?

Answer 1

Answer:

43 questions in total

Step-by-step explanation:

the original equation with the unknown (total number of questions on the test) will look like this

$\frac{total \: number \: of \: questions \: on \: exam}{24 \: answered \: questions} = 80\%$

we know this because to work out a percentage in the 1st place you need the total ÷ number (in this case it's ÷ how many questions out of the total she did answer)

now you rearrange.

you need to move the 24 to get the total on it's own here's how you do it

$\frac{tot \: num \: of \: qs}{24} \times 24 = 80\% \times 24$

what you do to one side of equation you have to do to the other. the 24 and 24 on the left will cancel because 24÷24=1 and we don't write

got mum of Q's x 1= 80 x 24

now you convert % to decimal

$80\% \times 100 = 0.80$

replace

$tot \: num \: qs \: = 24 \times 0.80 = 19$

now you take the original and + the 19

$24 + 19 = 43$

therefore there are a total of 43 questions on the exam