South African Class GMA 4-8-2+2-8-4 South African Class GMA 4-8-2+2-8-4 The South African Railways Class GMA 4-8-2+2-8-4 of 1954 was an articulated steam locomotive. Between 1954 and 1958, the South African Railways placed 120 Class GMA Garratt articulated steam locomotives with a 4-8-2+2-8-4 Double Mountain type wheel arrangement in service. All the locomotives could be configured as either a Class GMA branch line or a Class GMAM mainline engine. This was the most numerous Garratt class in the world. The light rail branch line Class GMA and mainline Class GMAM Garratt locomotive, a single Class which could be configured for either branch line or mainline
1/2 + 1/4 + 1/8 + 1/16 + ⋯ 1/2 + 1/4 + 1/8 + 1/16 + ⋯ In mathematics, the infinite series is an elementary example of a geometric series that converges absolutely. There are many different expressions that can be shown to be equivalent to the problem, such as the form: 2 + 2 + 2 + ... The sum of this series can be denoted in summation notation as: As with any infinite series, the infinite sum is defined to mean the limit of the sum of the first terms as approaches infinity. Multiplying by 2 reveals a useful relationship: Subtracting from both sides, As approaches