grandh01 wrote:How much tea worth 0.93$ per pound
must be mixed with tea worth $0.75
per pound to produce 10 pounds worth
$0.85 per pound?
1) 2 2/9
2) 3 1/2
3) 4 4/9
4) 5 5/9
5) 9 1/2
OA is D
Well one of the short cut approach could be like this.
There are 2 kinds of Tea- $0.93/pound, & $0.75/pound to make $0.85/pound. Whenever 2 quantities are mixed to produce another mixture, weighted average concept comes into picture.
Approach 1
Since final mixture is $0.08 distant from Ist tea, & $0.10 distant from IInd Tea, hence more of Ist tea than IInd tea should be mixed(0.08<0.10). Total quantity mixed is 10 pound of 2 tea. There are 2 options that may be answer- Options D), & E). The closest rational answer should be D). We disqualify E, because 9 1/2 is almost all of Ist tea, only 1/2 pound of IInd tea.
Approach 2
When 2 quantities having weights as a, & b are mixed to get a mixture of x weight, then mixing ratio comes out to be [|b-x|/|x-a|].
With reference to this question, we can say that 2 tea should be mixed in the ratio of 0.10:0.08 = 10:8=5:4.
So the quantity of Ist tea out of 10 pounds would be 5/4*10=5 5/9 pound.
