Mr Tan earns $4200 per month. His wife earns 6/7 as much as Mr. Tan. Mr. Tan saves 1/5 of his salary and Mrs. Tan saves 1/8 of her salary. How much do they save together per month?

Mr Tan earns 4200

Mrs Tan earns 6/7 * 4200 = 3600

Mr Tan saves 1/5 * 4200 = 840
Mrs Tan saves 1/8 * 3600 = 450

add 'em up to get 1290

1260

To find out how much Mr. Tan's wife earns, we can multiply Mr. Tan's salary by 6/7. Let's calculate it:

Mrs. Tan's salary = (6/7) * $4200
Mrs. Tan's salary = $3600

Now, let's calculate how much Mr. Tan saves per month. He saves 1/5 of his $4200 salary. We can find that amount by multiplying:

Mr. Tan's savings = (1/5) * $4200
Mr. Tan's savings = $840

Similarly, let's calculate how much Mrs. Tan saves per month. She saves 1/8 of her $3600 salary:

Mrs. Tan's savings = (1/8) * $3600
Mrs. Tan's savings = $450

Finally, to find out how much they save together, we simply add their individual savings:

Total savings = Mr. Tan's savings + Mrs. Tan's savings
Total savings = $840 + $450
Total savings = $1290

Therefore, Mr. Tan and Mrs. Tan save together a total of $1290 per month.