## Search found 7 matches

Thu Jan 23, 2020 2:49 pm
Topic: BdMO National Junior 2019/6
Replies: 4
Views: 6786

### Re: BdMO National Junior 2019/6

Arifa wrote:
Sun Jan 19, 2020 10:21 pm
$2(POS) = 2 ( (2019+x)/4 - 2019/2) = x/2 + 2019/2$
There is a typo , $sorry$ the $2nd$ equation should be-
$2(POS) = x/2 - 2019/2$
Sun Jan 19, 2020 10:21 pm
Topic: BdMO National Junior 2019/6
Replies: 4
Views: 6786

### Re: BdMO National Junior 2019/6

$Solution:$ Let x be the area of $BOC$ ; $(OQR) = (SOR)$ & $(POS) = (PQO)$ then,
$2(OQR) = 2(1010 - (2020+x)/4 ) = 2020 -1010 - x/2$
$2(POS) = 2 ( (2019+x)/4 - 2019/2) = x/2 + 2019/2$
$2(OQR) + 2(POS)= 2020-1010- (2019/2) = 1/2$
Implies, $(PQRS) = 1/2$
Fri Mar 22, 2019 11:41 am
Forum: Secondary Level
Topic: BdMO 2017 Dhaka divitional
Replies: 3
Views: 2068

### Re: BdMO 2017 Dhaka divitional

samiul_samin wrote:
Sun Feb 10, 2019 3:59 pm
soyeb pervez jim wrote:
Wed Mar 28, 2018 8:04 pm
For any rational numbers $x, y$ function $f(x)$ is a real number and $f(x+y)=f(x)f(y)-f(xy)+1$. Again $f(2017)\neq f(2018)$. $f(\frac{2017}{2018})=\frac{a}{b}$.Where $a,b$ are co-prime $a+b=?$
Hint

হিন্ট টা কিভাবে আসলো?
Tue Mar 05, 2019 10:03 pm
Forum: Social Lounge
Replies: 53
Views: 12723

Hello people,
I am Arifa. Lives in Dhaka and l like music, literature and art
Mon Mar 04, 2019 3:12 pm
Topic: BdMO National Junior 2019/3
Replies: 2
Views: 751

### Re: BdMO National Junior 2019/3

The length of HG = 10 (By 3-4-5 triangle ratio)
so DGH = 24= 10 ×0.5× DL
So, DL= 4.8
the area of EFGH= ABCD - 2 (AEB + EBF) = 108-60=48

it can be written as,
EFGH=LI×10
LI=4.8
SO,

DJ = 4.8×2 =9.6
Wed Dec 19, 2018 10:21 pm
Topic: BDMO 2018 junior 10
Replies: 12
Views: 2124

### Re: BDMO 2018 junior 10

Ummm, Angle AOC =130 Is the correct answer
Tue Dec 04, 2018 11:12 am
Forum: Junior Level
Topic: IMO 1972
Replies: 1
Views: 895

### IMO 1972

Prove that, (2n)!(2m)!/n!m!(n+m)! is an integer. Where m, n is positive integer[*]