Set up an equation that can be used to solve the problem. Solve the equation and answer the question asked.
-Mary and her brother John collect foreign coins. Mary has four times the number of coins that John has. Together they have 175 foreign coins. Find how many coins Mary has.
A) 35 coins
B) 140 coins
C) 133 coins
D) 28 coins

Question

Quizplus · Accepted Answer

Let's use the variable "x" to represent the number of coins John has. According to the problem, Mary has four times the number of coins John has, which can be represented as 4x.

Together, they have 175 coins, so we can set up the equation:

x + 4x = 175

Simplifying this equation, we get:

5x = 175

Dividing both sides by 5, we get:

x = 35

This means that John has 35 coins. To find how many coins Mary has, we can substitute this value into the expression we came up with earlier:

4x = 4(35) = 140

So Mary has 140 coins.

Therefore, the best choice is B. Let's say John has x coins. Mary has four times as many coins as John, so she has 4x coins. Together they have 175 coins, so we can set up the equation:
x + 4x = 175
Simplifying the equation, we get:
5x = 175
Dividing both sides by 5, we get:
x = 35
So John has 35 coins. Mary has four times as many, so she has:
4x = 4(35) = 140
Therefore, Mary has 140 coins, making Choice B the correct answer.

Set Up an Equation That Can Be Used to Solve