National Science Olympiad Math Questions

Susi arranges the smallest natural numbers in ascending order for multiples of 2 and Wati arranges the smallest natural numbers in ascending order for multiples of 3. The sum of Susi's 25th number and Wati's 20th number is ....

• 100

• 110

• 115

• 125

Given the following pattern. ■ ♦ ♦ ● ▲ ▲ ▲ ■ ♦ ♦ ● ▲ ▲ ▲ .... The image that will appear at the 100th position is ....

• ■

• ♦

• ●

• ▲

The hundreds numbers x and y where x = apc and y = aqc satisfy the properties x - y = 50 and p + q = 11. The result of p × q = ....

• 24

• 28

• 30

• 50

Andi arranges whole numbers that are not prime or not multiples of 5, starting from largest to smallest. If the 10th number written by Andi is 102, then the 21st number is ....

• 83

• 84

• 86

• 87

If 1/4 × 1/q - 1/4 - 1/q = 13/2, then the value of q is ....

• -9

• -1/9

• 1/9

• 9

If a and b are positive integers that satisfy a^2 - b^2 = 63, then the following value is not a result of a × b ....

• 45

• 135

• 315

• 2915

Three numbers x, y, z are three consecutive multiples of n (for example: 6, 8, 10 are consecutive multiples of 2). The sum of these three numbers is 27 and the product of the smallest and largest number is 72. The difference between the largest and smallest number is ....

• 2

• 4

• 6

• 8

Given three friends, Ani, Budi, and Corry. Among the three, Ani is the youngest and Corry is the oldest. Ani and Budi's ages differ by 1 year, while Budi and Corry's ages differ by 2 years. Four years later, the total age of them is 76 years. The sum of Ani and Corry's ages now is ... years.

• 41

• 42

• 43

• 45

Pak Joni bought 13 kg of banana chips for Rp650,000. The banana chips are resold at a price of Rp15,000 per 250 grams. The maximum profit that Pak Joni will earn is ....

• Rp100,000

• Rp130,000

• Rp150,000

• Rp180,000

Naomi, Tori, and Eksa are playing a game in 10 rounds. The 1st, 2nd, and 3rd place in each round will receive points of 5 points, 3 points, and 0 points respectively. From all rounds, Naomi earned a total of 28 points. How many times at least did Naomi become 3rd place in all rounds of the game?

• 4 times

• 3 times

• 2 times

• 1 time