Let `R=gS-4` , when `S=8` and `R=16` . If `S=10` , then `R` is equal to (a) 11 (b) 14 (c) 20 (d) 21

If ^(20)C_(r+1)=^(20)C_(r-1), then r is equal to a.10 b.11 c.19d.12

If R = (x^(2)+2)/(x-3) and S =(x-1)/x , then find (a) R + S (b) R - S (c) R.S (d) R/S

In triangle ABC, if A-B=120^(@) and R=8r, where R and r have their usual meanings,then cos C equal (a) (3)/(4) (b) (2)/(3)(c)(5)/(6) (d) (7)/(8)

In a triangle ASBC, let /_C=pi/2. If r is the in radius and R is the circumrdius of the triangle then 2(r+R) is equal to (A) a+b (B) b+c (C) c+a (D) a+b+c

In Fig. 4.245, R S D B P Q . If C P=P D=11 c m and D R=R A=3c m . Then the values of x and y are respectively (FIGURE) 12 , 10 (b) 14 , 6 (c) 10 , 7 (d) 16 , 8

If (5+9+13+\ ddotto\ n\ t e r m s)/(7+9+11+\ ddotto\ (n+1)t e r m s)=(17)/(16) , then n= (a) 8 (b) 7 (c) 10 (d) 11

If p:q=3:4,backslash r:s=8:5backslash and backslash x:y=10:6 then psx:qry is equal to (16)/(25) b.(25)/(32) c.2 d.(75)/(32)

If z_1,z_2,z_3,z_4 are imaginary 5th roots of unity, then the value of sum_(r=1)^(16)(z1r+z2r+z3r+z4r),i s 0 (b) -1 (c) 20 (d) 19