Question:
Of the 3 numbers whose average is 70, the first is 1/9 times the sum of other 2. The first number is:
A32
B21
C14
D42
Answer:
B. 21
Explanation:
Let the three numbers = a,b and c a+b+c = 70x3 = 210 .....(1) and a=1/9 × (b+c) => b+c = 9a put b+c =9a in equation (i), we get a+9a = 210 10a=210 a=21 first number = 21