how many numbers between 25 and 400 are divisible by 11? what is their sum?

Question

anonymous · Answer

who can answer?

amistre64 · Answer

well, it starts with the number 33

anonymous · Answer

can u pls show the equation sir???

amistre64 · Answer

400-25 = 375 possible results

divide that by ll

375/11 = 34.1

so ill assume there is like 34 numbers in that

anonymous · Answer

and the sum sir?

amistre64 · Answer

there sum can be determined by the expression 33+11n

from n=0 to 34 most likely

anonymous · Answer

wait sir... 33+11n=????

anonymous · Answer

answer is 7480

amistre64 · Answer

34
11
--
34
  34
----
374
  11
----
385
  11
----
396  .... found a few more

amistre64 · Answer

pfft, for got to add 33 :)

374
+33
----
407

so it looks like 34 is too large and 33 is perfect

0 to 33

anonymous · Answer

this time i am right i double checked it

anonymous · Answer

can i ask for the solution sir??? because the solution is greatly needed

amistre64 · Answer

33+11n i s a good expression yes since the first number divisible by 11 is 33

anonymous · Answer

thanks sambhav

anonymous · Answer

how to get the n sir???

amistre64 · Answer

$$\sum_{0}^{33}33+11n=\frac{33}{2}(33+374)$$

anonymous · Answer

a=33
l=396
d=11
n=(396-33/11)+1=35
sum=(35)(2(33)+34(11))/2 =7480
use the formula i gave u earlier

amistre64 · Answer

http://www.wolframalpha.com/input/?i=table+%2833%2B11n%29%2C+n%3D0..33

anonymous · Answer

thanks to to all of you friends :D

amistre64 · Answer

the sum is 7293

anonymous · Answer

why is sambhav answer is different?

amistre64 · Answer

he most likely has a small error, or i do. but ive got the wolf to dbl chk me :) http://www.wolframalpha.com/input/?i=sum+%2833%2B11n%29%2C+n%3D0..33

anonymous · Answer

hey @amistre64  ur formu;lla is correctbut 
∑03333+11n=332(33+374) =6715.5

amistre64 · Answer

yeah, 374 should have been 396 :)  but i accounted for that afterwards

anonymous · Answer

you used another website for help
 i used my mind

amistre64 · Answer

at my age, the mind is not so good ;)

anonymous · Answer

whats the correct answer monsieurs???

amistre64 · Answer

i have to look at my left foot just to remember what color sock i need to put on the right foot :)

anonymous · Answer

∑03333+11n=(35/2)(33+396)=7507.5

anonymous · Answer

whats ur age

@amistre64

amistre64 · Answer

.... pretty old

anonymous · Answer

sambhav and amistre what again is the answer???

amistre64 · Answer

7293 is what i get

anonymous · Answer

pls wait for a minute pls sorry for the argument between us

anonymous · Answer

its just ok no hard feelings

amistre64 · Answer

0 to 33 is 34 numbers entotal

34(33+396)/2 = 7293

anonymous · Answer

its right tnx for all your help ive got 2 numbers to go can u cooperate me or help me sir???

amistre64 · Answer

between the both of us, we are sure to work out all the wrinkles ;)

anonymous · Answer

@bienes_joshua  the write answer is 7293

anonymous · Answer

much thanks of all your help i just need to finish the 2 problems i will close this question and write a new one :D

amistre64 · Answer

starting an index at 1 makes life easier on the count but adds a little bit of complexity to the expression; therefore a modification that is equal is:$$\sum_{1}^{34}33+11(n-1)$$