Question of the Day

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10/3 , 11/7

Jul
30
2015
14,880 responses
Question of the Day Statistics
Number Answered
Correct 7,860
Incorrect 7,020
52% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer. 

All numbers divisible by both 4 and 15 are also divisible by which of the following?

Answer Choices

Hint

“Divisible by” means that the remainder is zero after the division. For example, 8 is divisible by 4, but it is not divisible by 3. Think of some numbers that are divisible by both 4 and 15, and then test these to see if they are also divisible by the numbers given as answer choices.

Question of the Day

Can you answer today's question?

Register Next Tests:
10/3 , 11/7

Jul
30
2015
14,880 responses
Question of the Day Statistics
Number Answered
Correct 7,860
Incorrect 7,020
52% correct

Mathematics > Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer. 

All numbers divisible by both 4 and 15 are also divisible by which of the following?

Answer Choices

Answer

All numbers divisible by both 4 and 15 are the multiples of 4 and 15. Since 4 and 15 have no prime factor in common (4 = 2^2 comma 15 = 3 times 5), then the least common multiple of 4 and 15 is equal to their product, namely 4 times 15 = 60. Every other multiple of 4 and 15 is divisible by 60. Thus, if 60 is divisible by a number then all the multiples of 4 and 15 are divisible by that number. Therefore, it is enough to check by which number in the given options is 60 divisible. Only 6 divides 60 and none of the other do. The answer must be (A).