Lisa and Robert have taken the same number of photos on their school trip. Lisa has taken 3 times as many photos as Claire. Robert has taken 12 more photos than Claire. How many photos has Claire taken?

Lisa and Robert have taken the same number of photos on their school trip. Lisa has taken 3 times as many photos as Claire. Robert has taken 12 more photos than Claire. How many photos has Claire taken?

Detailed Explanation

Call the number of pictures Claire taken is x. Lisa has taken 3 times as many photos as Claire then Lisa took is 3x. Robert has taken 12 more photos than Claire then it is x+12. Lisa and Robert have taken the same number of photos: 3x = x+12. Solve the equation we have x=6.