Solve the Problem $\frac { \mathrm { dy } } { \mathrm { dt } } = - 0.7 \mathrm { y }$

question 31

Multiple Choice

Solve the problem.
-In a chemical reaction, the rate at which the amount of a reactant changes with time is proportional to the amount present, such that $\frac { \mathrm { dy } } { \mathrm { dt } } = - 0.7 \mathrm { y }$ , when $\mathrm { t }$ is measured in hours. If there are $78 \mathrm {~g}$ of reactant present when $t$ $= 0$ , how many grams will be left after 4 hours? Give your answer to the nearest tenth of a gram.

• A) 4.7 g
• B) 2.4 g
• C) 0.1 g
• D) 7.1 g

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Definitions:

Expenses Overstated

A situation where the recorded amount of expenses is higher than the actual amount incurred, causing an understatement of net income.

Adjusting Journal Entry

a bookkeeping entry made at the end of an accounting period to allocate income and expenditure to the period in which they actually occurred.

Net Income

The remaining income of a company once all taxes and costs are deducted from its total revenue.

Depreciation Expense

The systematic allocation of the cost of a tangible asset over its useful life, representing the wear and tear, or obsolescence of the asset.