There is a typo , $sorry$ the $2nd$ equation should be-

$2(POS) = x/2 - 2019/2$

- Thu Jan 23, 2020 2:49 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Junior 2019/6
- Replies:
**4** - Views:
**6786**

- Sun Jan 19, 2020 10:21 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Junior 2019/6
- Replies:
**4** - Views:
**6786**

$Solution:$ Let x be the area of $BOC$ ; $(OQR) = (SOR)$ & $(POS) = (PQO)$ then,

$2(OQR) = 2(1010 - (2020+x)/4 ) = 2020 -1010 - x/2$

$2(POS) = 2 ( (2019+x)/4 - 2019/2) = x/2 + 2019/2$

Adding those 2 equations,

$2(OQR) + 2(POS)= 2020-1010- (2019/2) = 1/2$

Implies, $(PQRS) = 1/2$

$2(OQR) = 2(1010 - (2020+x)/4 ) = 2020 -1010 - x/2$

$2(POS) = 2 ( (2019+x)/4 - 2019/2) = x/2 + 2019/2$

Adding those 2 equations,

$2(OQR) + 2(POS)= 2020-1010- (2019/2) = 1/2$

Implies, $(PQRS) = 1/2$

- Fri Mar 22, 2019 11:41 am
- Forum: Secondary Level
- Topic: BdMO 2017 Dhaka divitional
- Replies:
**3** - Views:
**2068**

samiul_samin wrote: ↑Sun Feb 10, 2019 3:59 pmsoyeb pervez jim wrote: ↑Wed Mar 28, 2018 8:04 pmFor 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 $a+b=?$HintAnswer

হিন্ট টা কিভাবে আসলো?

- Tue Mar 05, 2019 10:03 pm
- Forum: Social Lounge
- Topic: Chat thread
- Replies:
**53** - Views:
**12723**

Hello people,

I am Arifa. Lives in Dhaka and l like music, literature and art

I am Arifa. Lives in Dhaka and l like music, literature and art

- Mon Mar 04, 2019 3:12 pm
- Forum: National Math Olympiad (BdMO)
- Topic: BdMO National Junior 2019/3
- Replies:
**2** - Views:
**751**

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

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
- Forum: National Math Olympiad (BdMO)
- Topic: BDMO 2018 junior 10
- Replies:
**12** - Views:
**2124**

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**

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