Shopping-Based Problems
Shopping problems are where everything in this chapter comes together. A typical question describes a child going to a shop, buying a few things at given rates, paying with a note, and asks for the total cost, the change, or how much more money is needed. The method is always the same three steps: first work out the cost of each item by multiplying rate by quantity, then add the costs to get the total, and finally compare that total with the money in hand. If the money given is more than the total, you subtract to find the change; if it is less, you subtract the other way to find the shortfall. For instance, if a girl buys 2 books at Rs 30 each and pays with a Rs 100 note, the total is 2 x 30 = Rs 60 and the change is 100 - 60 = Rs 40. These problems test whether a child can pick the right operation for each step rather than just compute blindly, which is exactly the kind of reasoning CTET wants future teachers to recognise. Reading the question carefully to see what is actually being asked, the total, the change, or the shortfall, is half the battle.
✅ Solved examples
✏️ Practice — try these, take hints as needed
📝 Topic test — 8 questions
Auto-graded with full solutions; saved to your dashboard. Use the calculator and formula sheet (top-right) any time.
Key Concepts — Quick Reference
Rupees and paise
| Basic equivalence | 1 rupee = 100 paise |
|---|---|
| Decimal form | Rs 45.75 means 45 rupees and 75 paise |
| Paise to rupees | 250 paise = Rs 2.50 |
| Rupees to paise | Rs 3.05 = 305 paise |
Cost, profit and change basics
| Total cost | Total = sum of (price x quantity) for each item |
|---|---|
| Profit | Profit = Selling Price - Cost Price (when SP is more) |
| Loss | Loss = Cost Price - Selling Price (when SP is less) |
| Change | Change = Amount Given - Total Cost |