## Search found 10 matches

Mon Aug 20, 2018 11:59 am
Forum: Higher Secondary Level
Topic: Geometry problem
Replies: 0
Views: 4406

### Geometry problem 38284439_476023639539494_8805193864634695680_o.jpg (94.83 KiB) Viewed 4406 times
Wed Jan 11, 2017 4:52 pm
Forum: Algebra
Topic: 2015 regional Secondary no. 6 function algebra
Replies: 4
Views: 2575

### Re: 2015 regional Secondary no. 6 function algebra

thank you for pointing out my mistakes asif vai though i can not edit it . But i was trying to mean f(x) by F(x) and i didnt think of it as a problem and by the next statement i meant f(5^k)=((5^k)*(2^(k-2)))+2^(k-3). I didnt mention it because it would look hideous .
Mon Jan 09, 2017 1:15 pm
Forum: Divisional Math Olympiad
Topic: Dhaka regional higher secondary/8
Replies: 3
Views: 2497

### Re: Dhaka regional higher secondary/8

I think F(2015)=420. Because F(5*384)=F(1920)=420=F(5)+F(384)=F(5) and F(384)=0 because 5 does not divide 384 . So F(2015)=F(5*13*31)=F(5)+F(13)+F(31)=F(5)=420
Mon Jan 09, 2017 12:23 pm
Forum: Secondary Level
Topic: Dhaka regional 16 P4
Replies: 5
Views: 2986

### Dhaka regional 16 P4 Untitled.png (44.57 KiB) Viewed 2986 times
Mon Jan 09, 2017 12:04 pm
Forum: Algebra
Topic: 2015 regional Secondary no. 6 function algebra
Replies: 4
Views: 2575

### Re: 2015 regional Secondary no. 6 function algebra

Suppose F(x)=ax+b , then F(F(x))=(a^2)x+ab+b if we compare 4x+3 with (a^2)x+ab+b then we will get F(x)=2x+1 or F(x)=-2x-3 Considering the next statement we can be sure that F(x)=2x+1 .Hence F(2015)=(2*2015)+1=4031    Sun Jan 01, 2017 8:40 am
Forum: Secondary Level
Topic: Dhaka regional 16 P2
Replies: 1
Views: 1490

### Dhaka regional 16 P2 Untitled.png (66 KiB) Viewed 1490 times
Sat Dec 03, 2016 10:22 am
Forum: Physics
Topic: height of a well
Replies: 1
Views: 1676

### Re: height of a well

Is the answer approximately 29.8369 m ?
Mon Aug 01, 2016 9:38 am
Forum: Secondary: Solved
Topic: Dhaka Secondary 2009/12
Replies: 3
Views: 4480

### Re: Dhaka Secondary 2009/12

Look carefully triangle AEF and triangle FGD are similar and AF/DF =1/3 so DG=3AE=3 and then we can use Pythagoras and obtain the value of the hypotenuse and the triangle EFG is right so the so answer would be half the value of the hypotenuse
Mon Jul 25, 2016 11:31 pm
Forum: Secondary Level
Topic: An Easy Geometry Problem
Replies: 2
Views: 2057

### Re: An Easy Geometry Problem

The answer is 2 . The area of the base of the pyramid or the equilateral triangle is 3 square root /2 and the length of the altitude from the top of the pyramid is 2/3 square root hence the volume must be 1/3 and 3-1=2
Fri Jul 22, 2016 12:47 pm
Forum: Secondary: Solved
Topic: Dhaka Secondary 2009/8
Replies: 8
Views: 6787

### Re: Dhaka Secondary 2009/8

We can easily show that triangle FCD and triangle EDB are similar . So FD/DE = CD/BD = FC/BE . Again we can see that triangle FCD and triangle BCD are similar . Again FD/CD = CD/BD = FC/BC .If we merge the conclusions we get FD/CD = FC/BC = FD/DE = CD/BD = FC/BE . We have FC/BC = FC/BE hence BC=BE ....