Current ratio and quick ratio

A company has current assets of $1·8m, including inventory of $0·5m, and current liabilities of $1·0m. What would be the effect on the value of the current and acid test ratios if the company bought more raw material inventory on three months’ credit? Current ratio Acid test A  Increase Increase B  Decrease Increase C  Increase Decrease D  Decrease Decrease The correct answer is D, both ratios will decrease. The opening current ratio (current assets /current liabilities) is $1.8m/$1.0m = 1.8, and the opening acid test (current assets less stock/ current liabilities) is $1.3m/$1.0m =1.3. The answer continued with this: Purchasing (say) $1.0m of inventory on short term credit will decrease the current ratio to ($1.8m + $1m)/ ($1.0m+ $1.0m) = 1.4. The acid test would also decrease to $1.8m/ ($1.0m+ $1.0m) = 0.9. I do not understand this last paragraph sir. Why we calculate Current assets for both current ratio and quick acid test ratio that way? Why the new current assets become $1.8m + $1m for current ratio and why the quick ratio suddenly becomes $1.8m? Shouldn't the quick ratio be Current assets of $1.3m?