# Maths doubts

Iâ€™m on my way home will help you once I reach.

Thanks!

50th D?

46 d?

Manan answer key not yet releasedâ€¦Pl could you send pic of solutionsâ€¦thanksâ€¦

Any other efficient method?

For the other question, if time permits, can manually calculate cube of 999 **if time permits**(which is quite stupid but is very high likely to get the right answer.)

Thanks @Ani_Ark please can you try others alsoâ€¦ Answerkey not out but your solution seems to be correct!!

Guys please helpâ€¦

Bro my tab camera not working. Canâ€™t upload. I can tell the approach tho.

Yes pleaseâ€¦

50th can be written as:

(1012-1)(1012+1)(1012+3)

= (1012^2 -1)(1012+3)

= 1012^3 + 2 1012 -3

So remainder is -3 which is 8.

4th Ya correct way, hit and trial

46th is lengthy. You need to count the digits.

[1-10) 9 digits.

[10 to 20) 2Ă—10 digits

So, [10 to 1) 9Ă—2Ă—10 digits.

Similarly write for 3 digit numbers.

Thanks bro

Guys did anyone get this

Sorry bro