Box A Had 130 More Erasers Than Box B. Then, 40 Erasers Were Transferred From Box B To Box A. In The End, There Were 8 Times As Many Erasers In Box A

Box A had 130 more erasers than Box B. Then, 40 erasers were transferred from Box B to Box A. In the end, there were 8 times as many erasers in Box A as Box B. How many erasers were there in Box A in the end?

 

Answer:

There were 240 erasers in Box A in the end.

Step-by-step explanation:

Represent:

Box B: x

Box A: y

Original quantity of erasers in Box A, y:

y = x + 130

Represent new quantities when 40 erasers were transferred to Box A:

x + 130 + 40

Box B:

x - 40

Equate the expressions when the new quantity of Box A is eight times the new quantity in Box B:

x + 130 + 40 = 8 (x - 40)   ⇒   Equation

Find the original number of erasers in Box B, x:

x + 170 = 8x - 320

8x - x = 170 + 320

7x = 490

7x/7 = 490/7

x = 70  ⇒  original number of erasers in Box B.

The original number of eraser in Box A, y:

y = x + 130

y = 70 + 130

y = 200  ⇒  original number of erasers in Box A

When 40 erasers were transferred from Box B to Box A:

Box B = 70 - 40

Box B = 30 erasers

Box A = 200 + 40

Box A = 240 erasers

There were 240 erasers in Box A in the end.