Number of students in a class at first

[Johnx1]

There were m pupils in a class at first. After a week, 4 more pupils joined the class.

a) Find the number of pupils in the class after a week in terms of m.

my answer: m + 4b) There were 40 pupils in the class after a week. How many pupils were there in the class at first?

my answer: no answer

I'm not sure about this question.

 

[MarkFL]

There were m pupils in a class at first. After a week, 4 more pupils joined the class.

a) Find the number of pupils in the class after a week in terms of m.

my answer: m + 4

Yes, that's good.

b) There were 40 pupils in the class after a week. How many pupils were there in the class at first?

my answer: no answer

I'm not sure about this question.

Here, they are telling you:

\(\displaystyle m+4=40\)

So, you need to solve for \(m\) to determine how many pupils were there in the class at first (because this is what \(m\) represents).

What do you find?

 

[Johnx1]

Thanks for the reply

There was a different answer that didn't make any sense to me.

The answer that I was given from the book was.

a) m - 20

b) 30.Is this incorrect?

 

[MarkFL]

Yes, I don't see how the answers given by your book could possibly be correct.