3rd and 4th Grade, October, 2018

    A.1201. The Gardener family is planting decorative trees in their huge garden. They planted twice as many Persian willows as Japanese maple trees, three times as many money trees as tulip trees. They planted 15 more Japanese maple trees than tulip trees, of which they planted 8. How many trees did they plant?

    A.1202. Last Sunday Aunt Rosie planted two bushes of forget-me-not’s, a white one and a blue one. She took good care of them so they started bearing flowers the following Sunday. The blue bush bloomed 10 flowers on Sunday and 10 more every day following that day. The white bush bloomed only one flower on Sunday but following that day the number of flowers on it doubled every day. On which day will the white bush have more flowers on it than the blue bush for the first time?

    A.1203. The Gardeners have two daughters, Violet and Freesia. Their father every year at this day plants twice as many trees in their huge garden as many years old his daughters are that year. Violet just turned 7 last month. How old is Freesia if her father has planted a total of 146 trees so far?

    A.1204. Violet and her sister are planting flowers into two big flower beds. They broke up the flower beds as shown on the diagram below. In each section they are planning to plant flowers of a single color. At least how many different colors of flowers do they need to use for each bed if they do not want to plant flowers with the same colors in two sections that share a border?

    A.1205. Freesia received a red, a blue and a white violet, and three pots of different shapes. How many different ways can she plant them if she may plant more than one flower into any pot?

    A.1206. Mr. Gardener is planning to spray his roses with chemicals against a bug attack. He bought 100 grams of chemicals, and wants to put them in boxes. At least how many boxes should he use (and how many grams in each box) so that by choosing a few boxes, he could take any whole number of grams of the chemicals without making any measurements when he wants to spray?

    A.1207. Mrs. Gardener extended the shorter side of the rectangular flower bed by 3 meters, and now she has a square shaped bed with an area that is 36 square meters more than the area of the original flower bed. What was the original area?

    A.1208. In Science class Freesia learned about small animals living in the forests. The heart rate of one of these animals could reach even 1000 beats per minute. This animal reproduces very quickly, a mother can have 5 to 7 babies 2 to 4 times a year. If there are 25 mothers living in the same area, what are the least and the most number of offsprings they can have in a year all together?

    Please send your solutions here.

    The Sharma Kamala Educational Trust is sponsoring the participation of students from India. So, if you are a student living in India, please, send your solutions to: Group A from India

    Back to Paul Erdős International Math Challenge

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