AIMO(2019)

13+16+19+22+25+28+31+34+37+40

• 265

• 688

• 64

• 264

When calculating the addition of two numbers, the tens digit 6 of one number is mistakenly written as 1, and the hundreds digit 4 of the other number is mistakenly written as 5. The resulting sum is 2019. What is the correct sum?

• 1987

• 1980

• 1969

• 1898

When a is even, 𝑓(𝑎)=𝑎÷2+5, otherwise 𝑓(𝑎)=(𝑎+1)×3+2. 𝑔(𝑎)=(𝑎−1)×3. Find the value of 𝑓(10)+𝑓(9)+𝑔(8).

• 34

• 63

• 67

• 43

There are 12 chickens and rabbits in the farm, with a total of 30 legs. Find the number of chickens. (Each chicken has 2 legs and each rabbit has 4 legs.)

• 5

• 4

• 76

• 9

Let m and n be natural numbers greater than 2019, and find the ones digit of multiplying n 7s and m 5s. (7×7×7×⋯×7×5×5×5×⋯×5)

• 65

• 54

• 5

• 45

Xiao Ai and Xiao Bei are 25 years old together, and Xiao Ai is 3 years older than Xiao Bei. How old is Xiao Ai?

• 13

• 33

• 14

• 12

Find the value of the expression 2222×333333

• 740665543

• 740665

• 7406659266

• 740665926

Give 8 identical candies to Xiaoai, Xiaobei and Xiaoke. Each person has at least one candy. How many ways are there?

• 45

• 021

• 045

Xiaoai and Xiaobei bought 58 books in total. If Xiao Ai gives 9 books to Xiao Bei, Xiao Ai will have 4 books less than Xiao Bei. So how many books did Xiao Ai buy at first?

• 36

• 56

• 26

• 15

Xiaoai, Xiaobei, Xiaoke and Xiaodi have a total of 2019 candies. It is known that the number of candies in Xiaoai is three times that of Xiaobei, and the number of candies in Xiaobei is 3 more than that of Xiaoke. The number of sugars is 6 more than twice the difference between the number of sugars between Xiao Bei and Xiao Ai. Find the number of sugars for Xiao Di.

• 34

• 99

• 67

• 902