In 40 seconds, Lola paints 40/8 = 5 rubber duckies. In the same time, Betty paints 40/10 = 4 rubber duckies. Thus in 40 seconds, they both paint 5+4 = 9 toys. It means that they need 40 seconds *= 40*4 = 160 seconds to paint 36 toys working together. ANSWER