0
Add your answer:
Earn +20 pts
What is the sum of all the multiples of 3 and 5 below 500?
The sum of all multiples of 3 below 500 is the sum of 3 + 6 + ... + 498 = 41583The sum of all multiples of 5 below 500 is the sum of 5 + 10 + ... + 495 = 24750Depending upon the interpretation of "of 3 and 5", the answer is one of:The sum of all multiples of both 3 and 5 below 500 is the sum of 15 + 30 + ... + 495 = 8415The sum of all multiples of 3 below 500 and all multiples of 5 below 500 is 41583 + 24750 = 66333Since the multiples of both 3 and 5 (that is 15, 30, ...) have been counted twice - once in the multiples of 3 and once in the multiples of 5 - the sum of all multiples of 3 or 5 or both below 500 is 41583 + 24750 - 8415 = 57918I have emphasised the word below with regard to 500 since 500 is a multiple of 5, but 500 is not below (less than) itself, that is the multiples are of the numbers 1, 2, 3, ..., 499. If the question was intended to mean less than or equal to 500, add an extra 500 to the multiples of 5 above, making the sum of the multiples of 5 be 25250 and the final sums (1) 8415, (2) 66833, (3) 58418.
What is the sum of all 2-digit multiples of 7 whose digits sum to a prime number?
-5
Find the sum of all the multiples of 3 or 5 below 1000?
Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.
What are all the multiples of 7 between 50 and 80?
56, 63, 70 and 77
What is the sum of the first 4 multiples of 5?
5 + 10+15+20=50 ans
What is the sum of all the multiples of 3 and 5 below 500?
The sum of all multiples of 3 below 500 is the sum of 3 + 6 + ... + 498 = 41583The sum of all multiples of 5 below 500 is the sum of 5 + 10 + ... + 495 = 24750Depending upon the interpretation of "of 3 and 5", the answer is one of:The sum of all multiples of both 3 and 5 below 500 is the sum of 15 + 30 + ... + 495 = 8415The sum of all multiples of 3 below 500 and all multiples of 5 below 500 is 41583 + 24750 = 66333Since the multiples of both 3 and 5 (that is 15, 30, ...) have been counted twice - once in the multiples of 3 and once in the multiples of 5 - the sum of all multiples of 3 or 5 or both below 500 is 41583 + 24750 - 8415 = 57918I have emphasised the word below with regard to 500 since 500 is a multiple of 5, but 500 is not below (less than) itself, that is the multiples are of the numbers 1, 2, 3, ..., 499. If the question was intended to mean less than or equal to 500, add an extra 500 to the multiples of 5 above, making the sum of the multiples of 5 be 25250 and the final sums (1) 8415, (2) 66833, (3) 58418.
The sum of all the multiples of 3 or 5 below 1000?
The multiple of 3 nearest to and below 1000 is 999. 999/3 = 333 The sum of all the multiples is 3 x 333 x 334/2 = 166833 The multiple of 5 nearest to and below 1000 is 995. 995/5 = 199 The sum of all the multiples is 5 x 199 x 200/2 = 99500
What is the sum of all 2-digit multiples of 7 whose digits sum to a prime number?
-5
What is the sum of the first 5 multiples of 5?
75
Find the sum of all the multiples of 3 or 5 below 1000?
Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.Well, you could add them one by one, or write a small computer program to do that, but here is a shortcut:Use the formula for an arithmetic series, to find the sum of all the multiples of 3 (3, 6, ... 999).Similarly for all the multiples of 5 (5, 10, ... 995).Add it all up.Multiples of 15 will be counted twice in his calculation, so you'll have to calculate the sum of all the multiples of 15, and subtract it from the above.
What are all the multiples of 7 between 50 and 80?
56, 63, 70 and 77
What is the sum of the first 5 multiples of 6?
90
What is the sum of the first 4 multiples of 5?
5 + 10+15+20=50 ans
What is the sum of all the multiples of 5 between 1 and 51?
All the multiples of 5 between 1 and 51 are: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 These add up to 275.
What 4 numbers are multiples of 5 and their sum is 80?
25,20,5,30
What a factor of 35 this number is odd this a multiple of 7 the sum digit of equal to 5?
The factors of 35 are 1, 5, 7, 35. All of them are odd. 7 and 35 are multiples of 7. 5 has a digit sum equal to 5. No number satisfies all of the conditions.
How can multiples of 10 also be multiples 5?
Since 10 is a multiple of 5, all multiples of 10 are multiples of 5.
