If parallelogram is concyclic then it is a rectangle justify

I want the solution of  ICSE maths book

If A is A invertible matrix of 3x3 and |A|=7 find |A inverse|

Who is Patwari

Prove that least perimeter of an isosceles triangle in which a circle of radius r can be inscribed is 6r root 3

Diagonals of rhombus are equal or not

X was employed with ABC ltd.He retired with 1.2.17 after completing a service of 24 years and 4months.He submits the following info

basic salary:₹25000 pm

da:100% of salary(40%of which forms part of retirement benefits)

last increment ₹2500 w.e.f 1.7.16

he recd leave encashment amounting to ₹280000 on account of accumulated leave of 240 days.He was entitled to 40 days leave for every year of service.

compute taxable leave encashment.

Why don't we place the value of pie in few questions ?