Q.1 Amina thinks of a number and subtracts from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?
Let us assume that the number Amina thought was x.
As per the question,
Transposing 3x to the LHS and -20 to the RHS, we get
8x - 3x = 20
or 5x = 20
Dividing both sides by 5.
x = 4
Therefore the number Amina thought was 4.