ICSE − Q & A

Can someone comment down the list of commonly asked prove that sums for circles? Please..Thanks :))

Why are girls so weak in maths?

http://www.respaper.com/king991999/7172-pdf.html Q.4(b)- What answer do you get? I got 10.15 sq.cm 

Also, In a sales tax question, when we're asked to find the profit of the seller, do we include the sales tax while calculating profit. (Kinda confused because I thought we weren't supposed to until I saw it in a book)

any commerce student

While fimding d mean, if d class interval is given less than something, for eg-less than 10, less than20, then do we take it to be 1-10 or 1-9??

Tan 2A = cot(A-18). Where 2A is an acute angle. Find A. Was this stupid?

Why is it wrong to draw an ogive using a scale(I mean u do get the r8 answer using a scale r8)?

Prove : Quadrilateral formed by angle bisectors of cyclic quad. is also cyclic. Plz Help....:-)

http://www.respaper.com/shivansh2017/6082-pdf.html You will find notes for maths here. Very helpful indeed.
*I don't own anything.*

http://www.respaper.com/hhhhhhhp/4624-pdf.html# question 11 b
is the number of students given frequency or cumulative frequescive ?
according to me it should be cumulative because marks less than is given 
please confirm