If `P=pir+2r` and P=36cm, then find the value of r (in cm).

Find the value of r if 5P_r = 6P_(r-1)

If "^10 P_r=5040 , find the value of r .

If "^10 P_r=5040 , find the value of r .

If the area of a triangle is 100 sq ,cm, r_(1)=10cm and r_(2)=50cm, then find the value of (b-a)

In DeltaPQR , with /_Q at right angle, given that PR+QR=25 cm and PQ=5 cm . Find the value of : (i) sin P,cosP and tan P . (ii) sec R-cot P .

If ""^10 P_r=5040 , find the value of r.

If ^(10)P_(r)=5040, find the value of r

If .^(n+r+1)P_(2)=72and.^(n-r)P_(2)=12 then find the values of n and r.