Answer:
31
Step-by-step explanation:
Let number of ten dollar bills be x .
So, number of five dollar bills = 2 x
Total amount of money in the cash register = 620 dollars
Amount of money in total cash as a result of five dollar bills = 2 x × 5 = 10 x dollars
Amount of money in total cash as a result of ten dollar bills = x × 10 = 10 x dollars
According to question ,
Total amount of money in the cash register = Amount of money in total cash as a result of five dollar bills + Amount of money in total cash as a result of ten dollar bills
⇒ 620 = 10 x + 10 x
⇒ 620 = 20 x
⇒ x = = 31
So, number of ten dollar bills = 31