A box is filled with table-tennis balls. 4/9 of the balls are yellow. 60 balls are white and the rest of the 40 balls are pink. How many table-tennis balls are there in the box?
The total fraction of balls that are yellow and pink is 4/9 + 0 = 4/9 of the balls.
Let X be the number of tennis balls in the box.
So the amount of balls that are yellow and pink is (4/9)*X.
The rest of the balls, or (5/9)*X, are white.
So the total amount of tennis balls in the box is X = (4/9)*X + (5/9)*X = (9/9)*X = X.
And 60 balls are white, so (5/9)*X = 60 balls.
Thus, X = (9/5)*60 = <<(9/5)*60=108>>108 tennnis balls. Answer: \boxed{108}.
Let's break down the information given step-by-step:
1. We know that 4/9 of the balls are yellow.
2. We also know that there are 60 white balls.
3. The remaining 40 balls are pink.
To find out the total number of table tennis balls in the box, we need to determine the number of yellow balls first.
Step 1: Find the number of yellow balls:
- 4/9 of the total number of balls are yellow.
- Let's represent the total number of balls as "x."
- The number of yellow balls can be calculated as (4/9) * x.
Step 2: Find the number of pink balls:
- We are given that the remaining 40 balls are pink.
- So, the number of pink balls is 40.
Step 3: Find the total number of balls:
- The total number of balls can be calculated as the sum of the yellow, white, and pink balls.
- So, the equation becomes (4/9) * x + 60 + 40 = x.
Now, we can solve the equation to find the value of x.
(4/9) * x + 60 + 40 = x
(4/9) * x - x = - 100
(-5/9) * x = - 100
x = (-100) / (-5/9)
x = -100 * (-9/5)
x = 180
The total number of table tennis balls in the box is 180.