Question 51133
D+Q=40 & 10D+25Q=490 THEN D=40-Q THUS 10(40-Q)+25Q=490 OR 400-10Q+25Q=490 OR

15Q=90 OR Q=90/15 OR Q=6 THEN D+6=40 OR D=40-6 OR D=34

PROOF 10*34+25*6=340+150=490 THUS THERE ARE 6 QUARTERS & 34 DIMES IN HIS JAR.