A woman composed the following riddle about her age:
Four times two and nine times three
Add that to my age and it will be
As much as two tens and a four
Plus twice my age exceeds a score.
Put into algebra, it simply means 4 ⋅ 2 + 9 ⋅ 3 + x = 2 ⋅ 1 0 + 4 + 2 ⋅ x − 2 0 . How old is the woman?
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Good Buddy..
i have one doubt how was -20 came in right hand side
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It is said in the riddle that 2 10 + 4 + 2x (being x the age) exceeds 4 3 + 9*3 + x by a "score", which is an english word that can be used to say 20.
How tough ! :P
I got 39 on my first try... just success on second try T_T
The score part was rally confusing...
Start by subtracting X from both sides, then notice that (2 x 10) - 20 = 0. You can do the rest in your head...
4 × 2 + 9 × 3 = 4 + X
8 + 27 = 4 + X
X = 31
That was what I got too
The true riddle is what a "score" means 😁
By dictionary definition, a score means a group of 20.
It means 20.
but how the score is twenty?
as in Four score and seven years ago...
Indeed it is... removing the equation wouldn't complicate everything a lot, just cause trouble to people who didn't know "score" also ment 20 before.
(4 X 2) + (9 X 3) + x = (2 X 10) + 4 + 2x - 20
8 + 27 + x = 20 + 4 + 2x - 20 ( combine like terms)
35 + x = 24 + 2x - 20 (transpose)
x - 2x = 24 - 35 - 20 (perform the operation)
-x = 24 - 55 ( subtract)
-x = -31
x = 31
(4•2)+(9•3)+x=(2•10)+4(2•x)-20. (Starting Equation) (8+27)+x=24+2x-20. (Distribute on both sides; add the 4 to 20) 35+x=4+2x. (Subtract the 20 from 24; add 8 and 27) 35=4+x. (Subtract x from the left side) 31=x. (Subtract 4 from the right side)
(4 * 2) + (9 * 3) + x = (2 * 10) + 4 + (2 * x) - 20
8 + 27 + x = 20 + 4 + 2x - 20
35 + x = 4 + 2x
35 - 4 = 2x - x
31 = x
4 X 2+9 X 3+x=2 X 10+4+2x-20 =>35+x=4+2x =>x=31 therefore the age of the woman is 31 years
how does -20 come ?? and it would b better if the equation was not given
i have a doubt how -20 came in the right hand side
Because the riddle states "exceeds a score", so you have do deduct 20 (a score) for the Right hand side.
4x2 + 9x3 + X= 2x10 + 4+2X-20 -X -X 8+27= 20+4-X-20 +20 +20 55=24+x -24 -24 31=x
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4 × 2 + 9 × 3 + x = 2 × 1 0 + 4 + 2 x − 2 0 8 + 2 7 + x = 2 0 + 4 + 2 x − 2 0 3 5 + x = 4 + 2 x x + 3 1 = 2 x x = 3 1