1. A certain chemical mixture should be in the ratio of 4 parts "A", 6 parts "B", and 2 parts "C". If a 15 kg batch is to be mixed, what quantities in kg of "A", "B", and "C" should be used in the batch?

A = 5, B = 7.5, and C = 2.5

A = 4, B = 6, and C = 5

A = 5, B = 6, and C = 4

A = 4.5, B = 6.5, and C = 4

A = 3.5, B = 5.5, and C = 6

2. A chemical mixture should be in the ratio of 9 parts "A", 2 parts "B" and 5 parts "C". A 64 kg batch is to be mixed. What quantity of "A" is required?

52.36 kg

36 kg

20 kg

8 kg

2.25 kg

3. A driving gear has 60 teeth and turns at 750 rpm. The driven gear has 90 teeth. What is the speed of the driven gear in rpm?

1125

1000

500

450

400

4. A gear has 1000 teeth and revolves at 50 rpm. The driven gear has 32 teeth. How fast does it turn?

12.2 rpm

1562.5 rpm

609.8 rpm

640 rpm

390.2 rpm

5. A gear wheel 330 mm in diameter and revolving at a speed of 200 rpm drives a wheel 150 mm in diameter. Find the speed in rpm of the second gear: