How many marbles of each color were in the bowl in the end?
November 17th, 2009 | by admin |The number of gray marbles to black marbles in a bowl was in the ratio of 4:5. Later, 8 gray marbles were taken out and 20 black marbles were added into the bowl. After that, the ratio of gray marbles to black marbles became 4:11.
Beginning ratio:
= 4x to 5x
Ending ratio:
(4x – 
to (5x + 20) = 4 to 11
Base number (x):
4(5x + 20) = 11(4x –
20x + 80 = 44x – 88
5x + 20 = 11x – 22; 6x = 42
x = 7
No. of grey marbles:
= (4 * 7) – 8
= 28 – 8
= 20
No. of black marbles:
= (5 * 7) + 20
= 35 + 20
= 55
Answer: gray marbles, 20; black marbles, 55
4 Responses to “How many marbles of each color were in the bowl in the end?”
By Pokemonfan on Nov 17, 2009 | Reply
does the problem say how many marbles were in the bowl 2 begin with
References :
By rsnipes29512 on Nov 17, 2009 | Reply
4x-8: 5x+20=4:11
Work this out.
4x-8 will be the number of gray
5x+20 the number of black
References :
By falling.up13 on Nov 17, 2009 | Reply
Let g represent the number of grey marbles
Let b represent the number of black marbles
4g/5b – 8g + 20b = 4g/11b
how did we get this formula?
simple:
the ratio of grey to black marbles was 4:5, in other words, 4/5
so we get the first term, which is: 4g/5b
later, you took out 8 grey marbles
so we get a second term, which is: – 8g
then, we added 20 black marbles:
so we get a third term, which is: + 20b
after all of that adding and taking out, we end up with a ratio of 4:11
so we get 4g/11b
thus, the formula: 4g/5b – 8g + 20b = 4g/11b
References :
By Jun Agruda on Nov 17, 2009 | Reply
Beginning ratio:
= 4x to 5x
Ending ratio:
to (5x + 20) = 4 to 11
(4x –
Base number (x):
4(5x + 20) = 11(4x –
20x + 80 = 44x – 88
5x + 20 = 11x – 22; 6x = 42
x = 7
No. of grey marbles:
= (4 * 7) – 8
= 28 – 8
= 20
No. of black marbles:
= (5 * 7) + 20
= 35 + 20
= 55
Answer: gray marbles, 20; black marbles, 55
References :