Moving with uniform acceleration a body covers 80 m in first 5s and 180m in next 5s.find initial velocity and acceleration

you know that with initial velocity v and acceleration a,

s(t) = vt + a/2 t^2

so,

5v + 25a/2 = 80
10v + 50a = 80+180

v=6 and a = 4

check:
s(t) = 6t + 2t^2
s(5) = 6*5 + 2*25 = 30+50 = 80
s(10) = 6*10 + 2*100 = 60+200 = 260 = 80+180