Question: in assembling a bluetooth device , a factory uses one of two kinds of modules . one module costs $ 15 and the other one , that is cheaper , costs $ 10 . the factory holds a $ 140 worth stock of 13 modules . how many of the modules in the stock are of the cheaper kind ?
A) 20
B) 25
C) 30
D) 11
E) 35
Correct answer: d
Grade: 7 | Topic: Expressions and Equations | Difficulty: Hard | Standard: 7.EE.B.3