Level 3
Olivia is 20% heavier than Xavier. Dana is 40% lighter than Xavier. Olivia is 12 kg heavier than Dana. What is Xavier's mass?

Level 3
Henry had to paint some cartons. On the first day, the number of cartons he painted was 40% of the number of cartons that he had not painted. One week later, he painted another 100 cartons. As a result, the total number of painted cartons became 28 more than ¹₂ of the total number of cartons. How many more cartons were unpainted than painted on the first day?

Level 3
Clifford had 80% fewer sweets than Ashwin. After Ashwin gave 210 sweets to Clifford, Clifford had ²₃ as many sweets as Ashwin. How many sweets did each of them have in the end?

1. Ashwin
2. Clifford

Level 3
Betty and Eva shared some stickers. Betty had 60% of what Eva had at first. Betty then gave Eva ³₇ of what she had. How many more percent did Eva have than Betty in the end? Correct the answer to 1 decimal place.

Level 3
Jeanne's school organized a trip to Japan. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 7 : 5. On the day of registration, 52 girls decided to withdraw and 52 more boys decided to join in. In the end, the number of girls who participated became 20% of the total participants for the trip. How many more boys than girls would visit Japan in the end?