Question

A collection of 108 coins containing only quarters and nickels is worth $21.

Which value could replace q on the chart?

21
108
21 – n
108 – n

Answer 1

TLDR: 108-n on Edge

Answer 2

The value could replace q is 108 - n ⇒ the last answer

Explanation:

* Lets study the values of quarters and nickles

- One quarter = 25 cents

- One nickle = 5 cents

- The number of coins is 108

- The coins are nickles or quarters only

- The coins worth $ 21

* Lets solve the problem

∵ The number of coins is 108 coins

- Let the quarter is q and the nickel is n

∴ q + n = 108 ⇒ (1)

∵ The coins worth $21

∵ $ 1 = 100 cents

∴ $21 = 21 × 100 = 2100 cents

∵ The quarter = 25 cents

∵ The nickels = 5 cents

∴ 25q + 5n = 2100 ⇒ (2)

- To find the value which replace q use equation (1)

∵ q + n = 108 ⇒ subtract n from both sides

∴ q = 108 - n

* The value could replace q is 108 - n