Sunita scores 10 marks for every question she answers correctly and loses 5 marks for every wrong answer. She answered 30 questions and scored 150 marks. How many questions did she get wrong?
Class 10Word Problems on Linear PairsAlgebra — Systems of Equations
A9
B20
C11
D10
Step-by-Step Solution
c+w=30,10c−5w=150. From first c=30−w.10(30−w)−5w=150,300−15w=150,15w=150,w=10.
Answer: D) 10
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