Multiple choice

The average of five numbers is 306.4. Average of first two number is 431 and last two numbers is 214.5. Find the third number.

  1. 239

  2. 241

  3. 243

  4. 245

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let the five numbers be a, b, c, d, e. Given: (a+b+c+d+e)/5 = 306.4, so sum = 1532. Also: (a+b)/2 = 431, so a+b = 862. And: (d+e)/2 = 214.5, so d+e = 429. Therefore c = 1532 - 862 - 429 = 241. This checks out: 1532 - 1291 = 241. Option D (243) would leave sum = 1534, which doesn't match.