Mean of 28, 30, 26, (K+6) and (K+1) is 25. Find the mean of 32, 39, and 2k.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 35
The mean of five numbers is 25, so their sum is \(5\times25=125\); this fixes K, and with it the third number of the new set.
Sum of the five numbers: \(28+30+26+(K+6)+(K+1)=2K+91\)
Setting it equal to 125: \(2K=34\), so \(K=17\)
The new numbers are 32, 39 and \(2K=34\)
Their mean: \(\displaystyle\frac{32+39+34}{3}=\frac{105}{3}=35\)