a1,a2,a3,.....,a10 are in AP common difference =−3 b1,b2,b3,......,b10 are in GP common ratio =2 Since, ck=ak+bk,k=1,2,3.......,10 ∴c2=a2+b2=12 c3=a3+b3=13 Now, C3−C2=1 ⇒(a3−a2)+(b3−b2)≠1 ⇒−3+(2b2−b2)≠1 ⇒b2=4 ∴a2=8 So, AP is 11, 8, 5, .... and GP is 2, 4, 8, .... Now,