Question

a)+15,+40,+65,+90,?,?​

Answer 1

a₁ = 15, a₂ = 40, a₃=65, a₄=90, a₅=?, a₆=?

r = a₂ - a₁ => 40 - 15 => r = 25

$a_{n}$ = a₁ + (n-1)r => a₅ = 15 + (5-1)25 => a₅ = 115

$a_{n}$ = a₁ + (n-1)r => a₆ = 15 + (6-1)25 => a₆ = 140