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 stickers does Mrs Lim have?
Let's assume Mrs. Lim has x stickers.
When she gives each pupil 3 stickers, she distributes a total of 3 * (number of pupils) stickers.
This means that 3 * (number of pupils) = x - 18.
Similarly, when she gives each pupil 5 stickers, she distributes a total of 5 * (number of pupils) stickers.
This means that 5 * (number of pupils) = x + 30.
Since the number of pupils is the same in both cases, we can equate the two expressions:
3 * (number of pupils) = 5 * (number of pupils) - 48.
Simplifying the equation, we get:
2 * (number of pupils) = 48.
Dividing both sides of the equation by 2, we find that the number of pupils = 48 / 2 = 24.
Substituting this value back into one of the original equations, we can find the number of stickers Mrs. Lim has:
x - 18 = 3 * 24.
Simplifying the equation, we find that x - 18 = 72.
Adding 18 to both sides of the equation, we find that x = 90.
Therefore, Mrs. Lim has 90 stickers. Answer: \boxed{90}.
Let's solve the problem step-by-step.
Let's assume the number of pupils in Mrs Lim's class is "p".
Step 1: If Mrs Lim gives each pupil 3 stickers, she will have 18 stickers left.
This can be represented by the equation: 3p + 18 = x, where x represents the number of stickers Mrs Lim has.
Step 2: If Mrs Lim gives each pupil 5 stickers, she will need another 30 stickers.
This can be represented by the equation: 5p - 30 = x.
Step 3: Now we have two equations:
3p + 18 = x
5p - 30 = x
Step 4: To find the number of stickers Mrs Lim has, we can equate the two equations:
3p + 18 = 5p - 30
Step 5: Simplify the equation:
48 = 2p
Step 6: Divide both sides of the equation by 2:
p = 24
Step 7: Substitute the value of p into one of the original equations to find the number of stickers Mrs Lim has:
3p + 18 = x
3(24) + 18 = x
72 + 18 = x
x = 90
Therefore, Mrs Lim has 90 stickers.