(Originais Teachy 2024) - Question Medium of Mathematics

João is in a candy store and wants to buy a chocolate bar that costs R$3.50. He hands a R$10.00 bill to the cashier. What is the change amount that João should receive? Select the correct alternative.

The Science class is learning about vegetable gardens and decided to plant a small rectangular garden at school, where they will grow lettuce and carrots. The garden's rectangle measures 3 meters in length and 2 meters in width. To find out how many plants will fit in the garden, they need to calculate the perimeter. Help the students calculate the perimeter of this rectangular garden.

João is organizing a birthday party and wants to make a larger quantity of his favorite cake recipe. The original recipe yields a cake with 20 slices and uses 3 cups of flour, 2 cups of sugar, and 1 cup of oil. João wants to make a cake with 40 slices. a) How many cups of flour, sugar, and oil should he use to make a cake that yields 40 slices? b) If he wanted to make a cake with 60 slices, what would be the quantity of cups of each ingredient? c) João noticed that the number of cake slices is always half the number of cups of water used in the recipe. How many cups of water are needed for a cake of 80 slices?