Answer:
Ryan bought 18 pens at Rite aid
Explanation:
In this question, we are to calculate the number of pens Ryan bought at Right aide
Let the number of pens Ryan bought at staples be x. Since each cost 60 cents each, the total amount of money he spent would be 60 * x = 60x cents
Let the number of pens bought at right aide be y. Now these pens cost 80 cents each. The total amount of money spent on these pens is 80y. We know that these amount is same as that spent at staples
Mathematically therefore,
60x = 80y•••••••••••(i)
The total number of pens bought is 42
Hence, mathematically
x + y = 42 •••••••(ii)
From ii we can see that x = 42 - y
Let’s now plug this into equation 1
60(42 - y) = 80y
2520 - 60y = 80y
140y = 2520
y = 2520/140
y = 18