Question

If we assign a variable x to the number of '8's that can be made using 42 matchsticks, then what would be the equation relating the number of matchsticks and the number of '8's that can be made using those many matchsticks?

• A. $x=7\times 42$
• B. $7+x=42$
• C. $7+42=x$
• D. $7x=42$

Answer 1

The correct option is D $7x=42$


As we see, the number of matchsticks required to make a single digit 8 is 7.
Now, if x is the number of 8s that need to be made, then the number of matchsticks required will be $7\times x=7x$
Now, since we have 42 matchsticks in hand, we need to find the number of 8s that can be made using 42 matchsticks
Hence, we equate 7x and 42, and solve for x
By finding the value of x, we get the number of 8s that can be made using 42 matchsticks
Hence, the equation is $7x=42$