Question

IN AN ENVELOPE THERE ARE SOME 5 RUPEE NOTE AND SOME 10 RUPEE NOTES.TOTAL AMOUNT OF THESE NOTES TOGETHER IS 350 RUPEES.NUMBER OF 5 RUPEE NOTES ARE LESS BY 10 THAN NUMBER OF 10 RUPEE NOTED. THEN FIND THE NUMBER OF 5 RUPEE AND 10 RUPEE NOTES

Answer 1

To which chapter does it belong to please tell me