Answer:
For graphic design I recommend the Microsoft Surface Book 2. Its specifications are: 
CPU: Intel Core i7 
Graphics: Intel UHD Graphics 620 - NVIDIA GeForce GTX 1060 
RAM: 16GB 
Display: 15-inch PixelSense (3240 × 2160) 
Storage: 256GB - 1TB SSD 
Price: $ 2499 at Amazon 
For the secretary I recommend a simple computer, with the following specifications: 
Processor: Intel Celeron G3900, with integrated GPU 
Motherboard: Basic range Skylake processor with an LGA1151 and chisept H110 socket model. 
RAM: 4 GB, with a DDR4 type module at 2,133 MHz 
Storage: 500 GB SATA hard drive at 7,200 RPM. 
Power supply and case: tower PC that includes integrated power supply 
Price: Approximately 197 euros 
Step-by-step explanation:
Microsoft Surface Book 2 is a great computer, ideal for graphic design. It can be used as a tablet and laptop. You have to separate the screen and draw using the included Surface Pen, or the Surface Dial. 15-inch display of 3,240 x 2,160 resolution, 16 GB of RAM, 1 TB disk storage and an NVIDIA GeForce GTX 1060. 
A PC for office automation in general terms is cost-effective, although it provides other advantages such as easy maintenance of both hardware and software.