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25 votes
25 votes
78 : 120 :: ? : 66
please give answer with explanation


User Yona
by
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1 Answer

10 votes
10 votes

Explanation:

Method 1:

Given that:

78 : 120 :: ? : 66

Here,

Product of extremes = 78 and 66

Product of means = 120 and ?

so,

(78*66) = (120 * ?)

⇛5148 = 120 * ?

⇛5148 = 120?

⇛120? = 5148

Shift the number 120 from LHS to RHS, changing it's sign.

⇛? = 5148/120

Therefore, (?) = 42.9

Method 2:

78 : 120 :: ? : 66

Convert each ratio into fraction.

⇛78/120 = ?/66

On applying cross multiplication then

since, (a/b) = (c/d) ⇛cd = ad

Where, a = 78, b = 120, c = ? and d = 66

Now,

⇛(120)? = (78)66

⇛120? = 5148

⇛(?) = 5148/120

Therefore, (?) = 42.9

Answer: Hence the value of (?) for the given problem is 42.9.

Verification:

Check whether the value of (?) is true or false.

78 : 120 :: ? : 66

Substitute the value of (?).

⇛78:120 = 42.9:66

Product of extremes should be equal to product of means.

Product of extremes:- 78*66 = 5148

Product of means:- 120*42.9 = 5148

⇛5148 = 5148

LHS = RHS

Hence, verified.

User Fraxture
by
2.7k points