Answer:
There were 12 girls in the group
Step-by-step explanation:
Assume that the number of girls at first is x
∵ There were x girls in a group
∵ Each girl pays 25 to use a boat
∴ The amount paid = 25 × x
∴ The amount paid = 25x
∵ If there had been 3 more girls in the group
→ That means add x by 3
∴ The number of girls in the group = x + 3
∵ Each would have paid 5 less
∴ Each girl would have paid 25 - 5 = 20
∴ Each girl would have paid 20
∴ The amount paid = 20 × (x + 3)
∴ The amount paid = 20(x) + 20(3)
∴ The amount paid = 20x + 60
→ Equate the right sides of the amount paid
∵ 25x = 20x + 60
→ Subtract 20x from both sides
∴ 25x - 20x = 20x - 20x + 60
∴ 5x = 60
→ Divide both sides by 5 to find x
∴ x = 12
∵ x represents the number of the girls in the group
∴ There were 12 girls in the group
