Question

Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has 1 more than 3 times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is 53?

Answer 1

Mark has 13 marbles

Don has 40 marbles

Explanation:

Let the number of Mark's Marbles = M

Let the number of Don's Marble = D

D = 1 + 3M - - - - (1) (Don has 1 more than 3 times the number of marbles Mark has)

D + M = 53 - - - - - (2) (total number of marbles is 53)

puttin the value of D from equation (1) into equation (2)

(1 + 3M) + M = 53

1 + 3M + M = 53

1 + 4M = 53

4M = 53 - 1 = 52

4M = 52

M = 52 ÷ 4

M = 13

finding D by putting the value of M (M = 13) into equation 1

D = 1 + 3M - - - - (1)

D = 1 + 3 (13)

D = 1 + 39

D = 40

∴ Mark has 13 marbles

Don has 40 marbles