Question

find sum of 10 terms of A.P. -1 , 1÷4 , 3÷2​

Answer 1

Answer:

• AP:-1,1÷4=0.25,3÷2=1.5
• Therefore,AP:-1,0.25,1.5
• a=-1,d=1.25,n=10S10=?
• Sn=n/2{2a+(n-1)d}
• S10=10/2{2×-1+(10-1)×1.25}
• S10=5{-2+9×1.25}
• S10=5{-2+11.25}
• S10=5{-9.25}
• S10=-46.25