Will give brainliest :)

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23

Leto [7]

Given :

All the natural numbers below 1000 that are multiples of 3 or 5 .

To Find :

The sum of all the multiples of 3 or 5 below 1000.

Solution :

Max multiple of 3 is 999 .

Max multiple of 5 id 995 .

So , number of multiple of 3 is :

$999=a+(n-1)d\\\\999=3+3(n-1)\\\\n=333$

Similarly for 5 .

$995=a+(n-1)d\\\\995=5+5(n-1)\\\\n=199$

Now , sum of all multiple of 3 is given by :

$S_3=\dfrac{n}{2}(2a+(n-1)d)\\\\S_3=\dfrac{333\times (2\times 3+332\times 3)}{2}\\\\S_3=166833$

Also , sum of all multiple of 5 is :

$S_5=\dfrac{n}{2}(2a+(n-1)d)\\\\S_5=\dfrac{199\times (2\times 5+198\times 5)}{2}\\\\S_5=99500$

Therefore , total sum :

$T=S_3+S_5\\\\T=166833+99500\\\\T=266333$

Now , there are some common number which we add two times like :

15 , 30 , 60 ......

So , we should subtract the sum of all multiple of 15 from T .

Now , sum of all multiple of 15 is 33165 .

So ,

$T=266333-33165\\\\T=233168$

Therefore , the sum of all the multiples of 3 or 5 below 1000 is 233168 .

8 0

4 years ago

Mikel gave a $1.32 tip for an order that cost $8.80

notsponge [240]

Answer:

1. Proportional

2. Not proportional

3. Not proportional

Step-by-step explanation:

Let's see what percentage of the $8.80 order is the $1.32 tip.

To find what percent a p[art is of a whole, divide the part by the whole and multiply by 100%.

$1.32/$8.80 * 100% = 15%

Mike's tip was $15% of the total.

1. $2.22 tip on $14.80 order

15% of $14.80 = 0.15 * $14.80 = $2.22

Tip is proportional

2. $1.86 tip on $10.50 order

15% of $10.50 = 0.15 * $10.50 = $1.58

Tip is nor proportional

3. Same as option 2 above.

7 0

3 years ago

What is this trinomial in factored form? 3a^2-2a-1

Dafna1 [17]

<span>Simplifying 3a2 + -2a + -1 = 0 Reorder the terms: -1 + -2a + 3a2 = 0 Solving -1 + -2a + 3a2 = 0 Solving for variable 'a'. Factor a trinomial. (-1 + -3a)(1 + -1a) = 0 Subproblem 1Set the factor '(-1 + -3a)' equal to zero and attempt to solve: Simplifying -1 + -3a = 0 Solving -1 + -3a = 0 Move all terms containing a to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + -3a = 0 + 1 Combine like terms: -1 + 1 = 0 0 + -3a = 0 + 1 -3a = 0 + 1 Combine like terms: 0 + 1 = 1 -3a = 1 Divide each side by '-3'. a = -0.3333333333 Simplifying a = -0.3333333333 Subproblem 2Set the factor '(1 + -1a)' equal to zero and attempt to solve: Simplifying 1 + -1a = 0 Solving 1 + -1a = 0 Move all terms containing a to the left, all other terms to the right. Add '-1' to each side of the equation. 1 + -1 + -1a = 0 + -1 Combine like terms: 1 + -1 = 0 0 + -1a = 0 + -1 -1a = 0 + -1 Combine like terms: 0 + -1 = -1 -1a = -1 Divide each side by '-1'. a = 1 Simplifying a = 1Solutiona = {-0.3333333333, 1}</span>

4 0

3 years ago

Round 87,298 to the nearest thousand

Marysya12 [62]

The answer is 90,000

6 0

3 years ago

Solve in details 2x+10=16

Ilia_Sergeevich [38]

Answer:

Solution for 2x-10=16 equation:

2x - 10 = 16

2x = 16 + 10

2x = 26 (divide both sides by 2 to get x)

2x/2 = 26/2

x = 13

Step-by-step explanation:

6 0

3 years ago