Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

Solve the mathematical equation in the picture below.

What's a single-digit number with no value?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

A little girl goes to the store and buys one dozen eggs. As she is going home, all but three break. How many eggs are left unbroken?

Check out the number list below and find what number comes next in the sequence.

111 , 113 , 117 , 119 , 123 , 137 , ?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

On the occasion of Diwali, online seller companies in India are offering a big discount on Iphone14 as below.

: Flipkart offers a Flat 65% discount
: Amazon offers a 10% discount over and over again.
: Shopclues offers RS.45,000 off.

If the original cost of the iPhone is Rs.70,000 Which is the best offer for you?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?