Multiple choice

In what ratio a mixture containing 20% milk should be mixed with another mixture containing 75% milk so that in the resultant mixture percentage of milk becomes 40%.

  1. 7 : 4

  2. 6 : 5

  3. 9 : 5

  4. 8 : 5

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Use alligation method. Mean concentration (40%) is closer to 75% than to 20%, so more of the 75% mixture is needed. The ratio is (75 - 40) : (40 - 20) = 35 : 20 = 7 : 4. This means mix the 20% and 75% mixtures in the ratio 7:4. Option A is correct.

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