Question

By the end of the school year, Terry had passed 80% of his science tests. If Terry failed 4 science tests, how many science tests did Terry pass?

Answer 1

We can say that 4 tests failed was 20%, and x tests passed was 80%: 4/20 = x/80
In this case, x = 16 tests passed.

Answer 2

Answer: Terry passed 16 science tests.

Step-by-step explanation: Given that by the end of the school year, Terry had passed 80% of his science tests and Terry failed 4 science tests.

We are to find the number of science tests that Terry passed.

Let x represents the total number of science tests that Terry appeared in.

Since he failed 4 science tests, so the number of science tests that Terry passes is given by

`(x-4).`

Since he passed 80% of his tests, so we get

`80\%* x=x-4\\\\\\\Rightarrow (80)/(100)* x=x-4\\\\\\\Rightarrow (4)/(5)* x=x-4\\\\\Rightarrow 4x=5x-20\\\\\Rightarrow 5x-4x=20\\\\\Rightarrow x=20.`

So, total number of science tests = 20.

Therefore, the number of science tests that Terry passed is given by

`n=20-4=16.`

Thus, Terry passed 16 science tests.