Question

Scarlett likes to knit sweaters for friends and family. Last fall, she knitted $1$ plain sweater, which took a total of $7$ hours. This fall, she knitted $5$ plain sweaters and $3$ patterned sweaters, which took a total of $65$ hours. If all the plain sweaters and all the patterned sweaters take the same amount of time to knit, how long does it take Scarlett to knit each type?

• A. It takes Scarlett $7$ hours to knit a plain sweater
• B. It takes Scarlett $7$ hours to knit a patterned sweater.
• C. It takes Scarlett $10$ hours to knit a patterned sweater.
• D. It takes Scarlett $10$ hours to knit a plain sweater

Answer 1

Answer: (A), (C)

The correct options are
A It takes Scarlett $7$ hours to knit a plain sweater
C It takes Scarlett $10$ hours to knit a patterned sweater.

Given that Scarlett takes $7$ hours to knit a plain sweater

Let the amount of time needed to knit a patterned sweater be $t$ hours

We have $5\times 7+3\times t=65$

$\Rightarrow t=10$ hours

Therefore options $A$ and $C$ are correct