1. A tensile test experiment conducted in the laboratory gave the following variations in readings:
The first, tenth and the last terms of the readings follow an arithmetic progression of 9, 40.5 and 425.5 respectively.
Find:
The number of terms
The sum of all the terms
The 70th term in the AP.
2. An oil company bores a hole 900 metres deep. The rig is shown below. Determine the cost of boring if the cost is £45 for drilling the first metre, with an increase in cost of £5 per metre for succeeding metres.
3. The value of a metal forming machine originally valued at £5,500.00 depreciates 12% per annum. Use (GP) to determine its value after 9 years, correct to the nearest pounds.
4. A model of a Variable 4 Speed Pulley shown below is to be re-design to be used in a drilling machine to have 6 speeds ranging from 150 rev/min to 900 rev/min. If the speeds form a Geometric Progression; determine their values, each correct to the nearest whole number.