Which one of the following is a prime number: 501, 509, 3024, 3715
509
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lifesaver
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rocket
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fairy
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thief
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15
Which one of the following is a composite number: 667, 677, 2021, 2027
667 = 23x29; 667: prime number; 2021 = 43x47; 2027: prime number
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boom
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fairy
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fairy
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baam
Lose 15 points!
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10
The area of a square garden is 10000 meter squared. Find the side of this garden?
10000 = 100 x 100 --> The side is 100 meter
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10
Find the square root for 576 by factorization
โ576 = โ(2ยณ x3)(2ยณ x3) = 2ยณ x3 = 24
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25
A class has from 30 to 40 students. Each boy brings 15 chocolate bars for a Teacher's Day party. The chocolate bars are shared equally among the 20 girl students and their teacher with no left overs. Find the number of Ss and chocolate bars
15 = 3x5, 21 = 3x7. Total bars = 3 x 5 x 7 x b = 105, 210,... if 105 bars -> 7 boys; if 210 bars -> 14 boys. There should be 10-20 boys -> 14 boys -> 34 Ss
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10
Find the lowest common multiple of 24 and 30
120
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10
Find the cube root for 512 by factorization
โ512 = โ8ยณ = 8
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seesaw
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seesaw
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rocket
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baam
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20
Kate wishes to cut some squares from a vanguard sheet of 64 cm x 48 cm. She likes the square to be as big as possible and she doesn't want any left over. Find the length of each square? How many squares can she cut altogether?
a) 64 = 2^6, 48 = 2^4 x 3. Side = GCF = 2^4 = 16 cm, b) 4 x 3 = 12 squares
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boom
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fairy
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rocket
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baam
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15
Car X and Car Y are at the starting point of a 2-km track race at the same time. Car X and car Y make one lap every 60s and every 80s respectively. How long does it take for both cars to be back at the starting point at the same time?
420s
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15
Find the smallest value of n such that the LCM of n and 15 is 45
15 = 3x5, 45 = 3^2 x 5 --> smallest n = 3^2 = 9
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10
Find the highest common factor of each of the following sets of numbersย ย ย ย a) 12 and 30 b) 15, 60 and 75
a) 6 b) 15
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15
The number 176 and 342, written as the products of their prime factors, are 176 = 2^4 x 11 and 342 = 2 x 3^2 x 19. Hence, find the smallest whole number that is divisible by both 175 and 342