A shopkeeper has 30 marbles. He sells 12 marbles to a customer, gives 2 marbles back to the customer as a discount, and then receives 5 more marbles as payment from another customer. How many marbles does the shopkeeper have now?

Step-by-step solution

1. After selling 12 marbles, remaining marbles: $30-12=18$.
2. Giving back 2 marbles reduces it to $18-2=16$.
3. Receiving 5 marbles increases it to $16+5=21$.

Concept tested: Sequential give and take

Published 7 October 2026 · How this solution was prepared and checked