How many children forgot to bring their money?

Question

A class of 25 students each contributed $1.50 to buy their teacher a present. However, a certain number of children forgot to bring their money and so the remaining children had to each contribute an extra 40c each. They received 50c change when they bought the present.
How many children forgot to bring their money?

Answer 1

Young,

 

So 25 students contributed $1.50 for the gift

 

So cost of gift is 25*1.50 = $37.50

 

Let x be number of students who forgot to bring money

Number of students who got money = (25-x)

Each paid $1.50 + 0.40 = $1.90 for gift

 

Total money paid = (25-x)*1.90

 

They received $0.50 change

 

So (25-x)*1.90 = 37.50 + 0.50

(25-x)*1.90 = 38

25-x = 20

x = 5

 

5 students forgot to bring money