Two unequal pairs of numbers satisfy the following conditions: (i) The product of the two numbers in each pair is 2160 (ii) The HCF of the two numbers in each pair is 12. If x is the mean of the numbers in the first pair and y is the mean of the numbers in the second pair, then what is the mean of x and y?
Two unequal pairs of numbers satisfy the following conditions: (i) The product of the two numbers in each pair is 2160 (ii) The HCF of the two numbers in each pair is 12. If x is the mean of the numbers in the first pair and y is the mean of the numbers in the second pair, then what is the mean of x and y? Correct Answer 72
Given:
HCF of the numbers in a pair = 12
Concept Used:
Mean = (First term + last term)/2
Calculation:
Let, the numbers be ‘12p’ and ‘12q’
Product of numbers = 2160
⇒ 12p × 12q = 2160
⇒ pq = 15
This is only possible when the values of p and q are either 1 and 15 or 3 and 5
Hence, the two pairs of numbers are (12, 180) and (36, 60)
⇒ Mean of first pair = x = (12 + 180)/2 = 96
⇒ Mean of second pair = y = (36 + 60)/2 = 48
Mean of x and y = (96 + 48)/2 = 72
∴ Mean of x and y is 72.