Simple Equation...

A number consists of two digits, whose sum is 8. If 36 is subtracted from the number, its digits are interchanged. Which of the following steps is/are required to find the answer.

Step 1: Let the units digit be x.
Step 2: Then, tens digit = 8 - x
Therefore, the number = 10 x (8 - x) + x
=> 80 - 10x + x = 80 - 9x
Step 3: Subtract 36 from this number, we get 44 - 9x.
Step 4: Number with digits interchanged is 10x + (8 - x) = 9x + 8
Step 5: 44 - 9x = 9x + 8
Step 6: The units digit is 2 and the tens digit is 6.
Step 7: Thus, the required number is 62.

Select the incorrect statement from the following:

A. To maintain an equation as equal or balanced, the same number is added to or subtracted from both sides of the equation.
B. If any number is present as the denominator on one side, then it will move to the numerator when transferred to the other side.
C. In order to maintain an equation as balanced, both sides should be multiplied or divided by the same number.
D. If a number bears a positive sign on one side of the equation, then it will keep its positive sign when moved to the other side of the equation.

Match the following:

You want to distribute 20 sweets among your classmates on your birthday. You are required to distribute equal number of sweets in each of the 5 rows of the class. Which of the following equations would you use to find the number of sweets (s) to be distributed in each row?

Solve the following equation for q:

25 - 2q = 15

Subtracting 10 from 15 less than thrice a number gives 20 as the result. The number is

Find the value of 'a' for the following equation to be true:

18 - (20 - 16 ÷ 4 × 4) + a = 60