Mrs Lim has some stickers to distribute to the pupils in her class. If she gives each pupil 3 stickers, she will have 18 stickers left. If she gives each pupil 5 stickers, she will need another 30 stickers. How many pupils are there in her class?
Let's assume there are 'x' pupils in Mrs Lim's class.
If she gives each pupil 3 stickers, she will have 18 stickers left.
This means she originally had 3*x + 18 stickers.
If she gives each pupil 5 stickers, she will need another 30 stickers.
This means she originally had 5*x - 30 stickers.
Therefore, 3*x + 18 = 5*x - 30.
Subtracting 3*x from both sides, we get 18 = 2*x - 30.
Adding 30 to both sides, we get 48 = 2*x.
Dividing both sides by 2, we get x = 48/2.
Hence, there are x = <<48/2=24>>24 pupils in Mrs Lim's class. Answer: \boxed{24}.
Let's assume the number of pupils in Mrs Lim's class is "x".
Given:
If Mrs Lim gives each pupil 3 stickers, she will have 18 stickers left.
If Mrs Lim gives each pupil 5 stickers, she will need another 30 stickers.
1) If each pupil receives 3 stickers:
Mrs Lim gives out 3x stickers.
Remaining stickers = Total stickers - Stickers given out = 18
So, 3x = 18
Divide both sides by 3:
x = 6
2) If each pupil receives 5 stickers:
Mrs Lim gives out 5x stickers.
She needs another 30 stickers.
So, 5x + 30 = Total stickers.
But, we already know from the previous calculation that x = 6.
Substituting the value of x:
5(6) + 30 = Total stickers
30 + 30 = Total stickers
Total stickers = 60
Therefore, there are 6 pupils in Mrs Lim's class.