Simple Equation...

Some children are sitting in a park. They have a certain number of chocolates. If each child eats 2 chocolates, then 2 extra chocolates will be left. If eat child eats 3 chocolates, then they will be short by 2 chocolates. Find the number of children and the number of chocolates, respectively.

Sum of two digits of a number is 7. When 27 is subtracted from this number, its digits get interchanged. Which of the following are correct steps to find the number?

I. Let tens digit be m.

II. Then, ones digit = (7 - m)
Number = 10 × m + (7 - m) = 9m + 7

III. Subtracting 27 from the number, we get 9m - 20.

IV. Number with its digits interchanged = 10 × (7 - m) + m

V. 9m – 20 = 70 – 9m

VI. Hence, the number = 52

Select the incorrect statement:

a. In an equation, whatever operation happens on the right side of equals sign also happens on the left side.
b. If a number is subtracted from one side of the equation, the same number is subtracted from the other side as well.
c. If one side of the equation is multiplied by a number, then the other side of the equation is multiplied by any other number.
d. If a number is added to one side of the equation, then the same number is added to the other side as well.

A shoe store has 48 pairs of shoes in black and brown colours only. Each black pair costs Rs. 1500 and each brown pair costs Rs. 1900. If the total earnings from the sale of all the pairs are Rs. 79,200, then

I. form an equation representing the case
II. find the number of pairs of black shoes
III. find the number of pairs of brown shoes

The solution of the equation 20 – 3p = 2 is