Question

Harrison has $ $9.30$in his coin collection, all in pennies and dimes. The number of dimes is three times the number of pennies. How many coins of each type does he have?

Short answer

The number of pennies are $30$and dimes are$90.$

Step-by-step solution

Step 1. Given Information

Total amount$=\$9.30$

Let he number of pennies be $x$

Therefore ,

According to the question,

number of dimes will be $3x$

Step 2. Solution of the equation 

Now, According to the question,

$$\begin{gathered} 0.01x+0.10\left(3x\right)=9.30 \\ 0.01x+0.30x=9.30 \\ 0.31x=9.30 \\ x=30 \\ Therefore, \\ 3x=3\times 30=90 \end{gathered}$$