9) The least common multiple (LCM) of two numbers is 168 and highest common factor (HCF) of them is 12. If the difference between the numbers is 60, what is the sum of the numbers?

10) Average diameter of 5 shafts is 23.6 cm. If a sixth shaft is also included, then the average diameter becomes 22.2 cm. What is the diameter of the sixth shaft?

11) The square root of 0.9 is

12) 20 divisions of a vernier scale, coincide with 19th divisions of main scale. Each main scale division is equal to 1 mm. What is vernier least count?

13) Seath for fitter, turner and welder in an industrial training institute are in the ratio of "4:5:6". There is a proposal to increase these seats by 25%, 40% and 50% respectively. The ratio of increased seat is