Question

Barb the baker creates a new temperature system for baking bread, Breadus, which is linearly based on Fahrenheit. Bread rises at $110\text{ F}^{\circ},$ which is $0$ on the Breadus scale. Bread bakes at $350\text{ F}^{\circ},$ which is $100$ on the Breadus scale. Bread is done when its internal temperature is $200\text{ F}^{\circ}.$ What is this temperature on the Breadus scale?

$33$

$34.5$

$36$

$37.5$

$39$

Answer: D

Concepts:linear equation slope

Difficulty rating: 1130

Solution:

The Breadus reading is linear in Fahrenheit through $(110, 0)$ and $(350, 100),$ so $B = \frac{100}{350 - 110}(F - 110)$ $= \frac{5}{12}(F - 110).$ Plug in $F = 200:$ $B = \frac{5}{12} \cdot 90 = 37.5.$ Therefore, the answer is D.

2023 AMC 10A Problem 8

Answer: D

Difficulty rating: 1130

Solution:

Problem 8 in Other Years