Question

Among three numbers, the first number is thrice the second number and one-fourth of
- the third number. The average of all three numbers is 64. What is the average of first
and third number?
(a) 30
(b) 24
(c) 90
(d) 48​

Answer 1

Answer:

(c)90

Step-by-step explanation:

let numbers be:

X/4,X/12,X

given

(X/4+X/12+X)/3 =64

X= 144

now

( X + X/4)/2 = (144+36)/2

=90

Answer 2

Answer:

30

Step-by-step explanation:

let first no. be 'x'

2nd no. = x/3 & 3rd no. = 4x

sum = 64

x + x/3 + 4x = 64

16x/3 = 64 => x = 12 (1st no.)

2nd no. = 12/3 = 4 & 3rd no.= 4×12 = 48

average of first and third number

= (12+ 48)/2 = 60/2 = 30

option(a) is correct