:morris gave his mother his savings of 105 bills, consisting of twenty-dollar and ten-dollar bills. after she counted the money, his mother told morris that he had $1,550. how
many ten-dollar bills did morris have?

ten-dollar bills = 55 pieces

Step-by-step explanation:

Given:

Total number of bills = 105

Total value = $1550

Assume:

twenty-dollar bills = x

ten-dollar bills = 105 - x

Solve:

20x + 10(105 - x) = 1550

20x + 1050 - 10x = 1550

10x + 1050 = 1550

10x = 500

x = 50

twenty-dollar bills = x = 50

ten-dollar bills = 105 - x = 105 - 50 = 55

Check:

twenty-dollar bills =50 x 20 = $1000

ten-dollar bills = 55 x 10 = $550

Total = $1000 + $550 = $1550

a is the correct