Level 3
Andy, Benjamin and Caleb had a total of 698 cards at first. After a week, the number of Andy's cards became 3 times the number of cards he had at first. The number of Benjamin's cards decreased by 138. Caleb had half as many cards as he had at first. In the end, the three boys had the same number of cards.

1. How many cards did Caleb have at first?
2. What was the total number of cards that the three boys had in the end?

Level 3
A convenience store sold crabstick, salmon and egg mayo sandwiches. The ratio of the number of crabstick sandwiches made to the total number of sandwiches made was 3 : 7. The ratio of the number of salmon sandwiches made to the total number of sandwiches made was 1 : 5. After the store sold some crabstick sandwiches and made another 42 salmon sandwiches, there was an equal number of crabstick, salmon and egg mayo sandwiches left. Find the number of crabstick sandwiches sold.

Level 3
During Christmas, Vincent's candle and Ethan's candle were placed on an altar. Vincent's candle was 3 cm longer than Ethan's candle. Vincent's candle and Ethan's candle were lit at 5:30 p.m. and 9:00 p.m. respectively. They burnt down to the same height at 10:30pm. At 1:30 a.m., Ethan's candle was burnt out while Vincent's candle was burnt out at 3:30 a.m. Find the original heights of Vincent's candle and Ethan's candle.

Level 3
²₅ of the crayons in a bag were red and the rest were blue and yellow. 20% of the blue crayons and 12% of the yellow crayons were thrown away. There was an equal number of blue and yellow crayons left. If there were 352 blue and yellow crayons left,

1. what was the number of red crayons?
2. what was the total number of crayons in the bag at first?

Level 3
¹₂ of the pupils in a school were girls and the rest were boys. ²₅ of the girls and ²₃ of the boys took part in a school event. 364 pupils did not take part. How many more girls were needed to take part in the school event so that it would be equal to the same number of boys who took part in the event?