Question 304952
let the number of chickens he has be x

ducks = 240+x

(240+x) -1/2(240+x)

So he has 1/2 (240+x) ducks

1/2 (240+x) +150 = x

120+1/2 x+150= x

240 +x +300 /2 = x
540+x=2x

x=540 number of chickens

Number of ducks = 540+240=780