Question

In a test (+4) marks are given for every correct answer and (-1) marks are given for every
incorrect answer. [3]
a) Mona answered all the questions and scored 30 marks though she got 10 correct
answers. How many incorrect answers did she attempt?
b) Bobby also answered all the questions and scored (12) marks though he got 4
incorrect answers. How many correct answers did he attempt?

Answer 1

Step-by-step explanation:

Let the no. of correct answers be x and incorrect answers be y

For Mona

$10 \times 4 + y( - 1) = 30 \\ 40 - y = 30 \\ y = 10$

No. of incorrect answers is 10

For Bobby

$x \times (4) + 4( - 1) = 12 \\ 4x - 4 = 12 \\ 4x = 16 \\ x = 4$

No of correct answers is 4