Question
The average of first three numbers of a set of six
numbers is 60 .The average of the second, third and fourth numbers is 20 and the average of the third, fourth and fifth numbers is 30. The average of last three numbers is 40. What is the average of first three and last three numbers of the set?Solution
We are given four conditions involving averages of groups of three numbers from a set of six numbers a,b,c,d,e,f:
We add these equations to get = a+2b+3c+3d+2e+f = 450 Then, using the known sums a+b+c =180 and d+e+f=120, we substitute them into the equation: 180+120+(b+2c+2d+e) = 450 This simplifies to:b+2c+2d+e=150 The total sum of all six numbers is 180+120 = 300. Therefore, the average of the first three and last three numbers is: 300/6 = 50
Select the correct option that indicates the arrangement of the given words in the order in which they appear in an English dictionary.
1. Specie...
In the given word “PLATINUM” which have as many letters between them in the word as in the English alphabetical series (both forward and backward)?<...
Select the number-pair in which the two numbers are related in the same way as are the two numbers of the given number pair.
13 : 338Â
In the following figure, square represents Intelligent, triangle represents Smart, circle represents Handsome and rectangle represents Students. Which o...
Who among the following writes the book three persons before T?
Read the given arrangement of numbers, letters, and symbols carefully and answer the questions based in it.
% 7 @ 8 3 % 9 N 4 7 M @ 6 N & 9 R #...
A group of letters are numbered from 1 to 8. Four options given below depict combinations of these numbers. Select that combination of numbers so that l...
If DBC = 18 and GFE = 36, then IJEF =
Select the set of numbers that is similar to the following set of numbers.
{19, 27, 35}
Q is related to S in a way, R is related to U in the same way then which of the following is related to O in the same way?