A country has three types of fighter planes: J7s, J8s and J10s. The ratio of the speed of a J7 to the speed of a J8 is 3:4. The ratio of the speed of a J8 to the speed of a J10 is 2:3.

(a) What’s the ratio of the speed of a J7 to the speed of a J8 to the speed of a J10?

(b) If the speed of a J7 is 330 kilometers per hour, what’s the combined speed of the three planes?