R/9 = -21
Multiply by 9
r = -189
Answer: Mark has 28 marbles while Don has 85 marbles.
Step-by-step explanation:
Let x represent the number of marbles that Mark has.
Let y represent the number of marbles that Don has.
If Don has 1 more than 3 times the number of marbles Mark has, it means that
y = 3x + 1
The total number of marbles is 113. It means that
x + y = 113- - - - - - - - - - - - 1
Substituting y = 3x + 1 into equation 1, it becomes
x + 3x + 1 = 113
4x + 1 = 113
4x = 113 - 1 = 112
x = 112/4
x = 28
y = 3x + 1 = 3 × 28 + 1
y = 85
You are told that sprinklers run for the same amount of time. lets refer to this time as T.
you are told that 4 sprinkles run one at a time for 50 minutes total. that means that T should be 50/4 = 12.5 minutes = 12 minutes and 30 seconds