Practice30Create account

An auto-rickshaw in Nagpur charges a fixed ₹40 plus ₹20 for every kilometre travelled. Ritu paid ₹180 for her ride. How far did she travel?

Class 7Simple EquationsSimple Equations
  • A9 km
  • B11 km
  • C4 km
  • D7 km

Step-by-Step Solution

Let the distance be k km. 20k + 40 = 180 → 20k = 140 → k = 7. Check: ₹40 + ₹20(7) = ₹180 ✓. Answer 9 divides ₹180 by ₹20 and forgets the fixed ₹40; 11 adds the ₹40 instead of subtracting it; 4 swaps the two charges, treating ₹40 as the per-kilometre rate.
Answer: D) 7 km

Key idea: The balance principle

An equation is like a balance scale: LHS on one pan, RHS on the other, and the scale is level. Whatever you do to one side, you must do to the other to keep it balanced. So if you add 5 to LHS, add 5 to RHS. If you divide LHS by 3, divide RHS by 3.

Goal: isolate the variable on one side. Get by itself by undoing every operation around it, in reverse order, applied to BOTH sides.

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Simple Equations practice questions

More Class 7 Simple Equations practice

In a quiz every correct answer scores 5 marks and every wrong answer loses 2 marks. Anil…The sum of three consecutive odd numbers is 81. What is the largest of the three?At a Diwali party a packet of 76 sweets is shared equally among 8 children, and 4 sweets…The three sides of a triangular park measure x m, (x + 6) m and (x + 9) m, and its…Two shelves hold the same number of books. The first has 4 equal stacks and 7 loose…