Question

5% less than 28% of x^2 is 10.Then what is 15 less than 28% of x^2.

Answer 1

5% =10
then 15%=30?

Answer 2

that is not 15%

Answer 3

sorry, i was just guessing.. 5 into 15 is 3 x 10.. anyway am wrong;.

Answer 4

5% of what is less than 28% ??

Answer 5

Dont know? But thats the complete question...

Answer 6

Can we take simply 5% ??

Answer 7

May be I am wrong..

Answer 8

The options are:
1,2,3,4

Answer 9

@mukushla can u help?

Answer 10

Let me try then..

Answer 11

Ok

Answer 12

i got 5 lol

Answer 13

How? @nickhouraney

Answer 14

28% of x^2 => 28/100 x X^2
5% less of that will be=> (28/100 x X^2) -5/100 = 10

Answer 15

me too 5

Answer 16

pretty sure its wrong haha

Answer 17

@ganeshie8 how?

Answer 18

I got -4.5

Answer 19

28% of x^2 : .28*x^2
5% of above : .05(.28*x^2)

combine :
.28*x^2 - .05(.28*x^2) = 10 -----------(1)
.28*x^2-15 = ? -------------------(2)

.28x^2(1-.05) = 10
.28x^2 = 20


plugin this in (2)

Answer 20

2.8*x^2-1.5

Answer 21

I also did the same @ganeshie8

Answer 22

u also got 5, right ?

looks like options are wrong !

Answer 23

ooooh i see how we did it wrong re-read the question

Answer 24

i used the equation .28x^2=10

Answer 25

PLZ check your calculation @ganeshie8

Answer 26

.28x^2(1-.05) = 10
then, .28x^2=10.5

Answer 27

got it? @ganeshie8

Answer 28

@nickhouraney How did you get that equation?

Answer 29

i think it should be:
.28*x^2 - .05(.28*x^2) = 10 -----------(1)
.28*x^2- .15( .28*x^2) = ? -------------------(2)
.28x^2(1-.05) = 10
.28x^2(1-.15) = 20 ???

Answer 30

hold up callisto let me check something

Answer 31

ack... yup! .05 i treated as .5 lol

Answer 32

5% less than 28% of x^2 is 10.

28% of x^2 => 0.28x^2

5% less than 28% of x^2
=> (1-5%) (0.28x^2) = 0.95 (0.28x^2)

5% less than 28% of x^2 is 10.
=> 0.95 (0.28x^2) = 10
0.28x^2 = 10/0.95

Then what is 15 less than 28% of x^2.

28% of x^2 = 10/0.95

15 less than 28% of x^2 => 10/0.95 - 15

Doesn't look right at all :|

Answer 33

nope i have no idea

Answer 34

Answer will be negative by using that..

Answer 35

That's why it doesn't make sense :(

Answer 36

Ya..... we all got -4.5

Answer 37

Something tricky in 5% part..

Of what part is 5% we have to be taken..

Answer 38

(5% less than 28% of x^2) =10

Answer 39

Yes but of what part 5% we should take??

Answer 40

Ya...... I agree with @waterineyes

Answer 41

could it simply be 23% of x^2 = 10?

Answer 42

I tried that also @nickhouraney

Answer 43

but gives no answer

Answer 44

dang lol

Answer 45

is there some way of setting up a system of equations with this?

Answer 46

For that we need to understand the problem at first

Answer 47

Problem solved I think..

Answer 48

@waterineyes how?

Answer 49

My screen is showing:

Satellite73 is typing a reply....


ha ha ha..

Answer 50

\(.95\times .28x=10\implies x=37.594\)

Answer 51

x^2

Answer 52

I think its x^2

Answer 53

maybe it is \(\chi\)

Answer 54

Ha ha ha..

Answer 55

what did you get @waterineyes

Answer 56

\(.85\times .28\times 37.594\) might do it

Answer 57

You took it seriously @nickhouraney

Answer 58

:-(

Answer 59

@nickhouraney i think the point is that to say 5% less than some P is A, means \(.95P=A\)

Answer 60

in other words, do decrease a number by 5% is the same as multiplying the number by \(.95\)

Answer 61

But that some number P is : \(\frac{28}{100}x^2\) and \(\frac{28}{100}x\)..

Answer 62

and not..

Answer 63

in fact we could say "let 28% of \(x^2\) be \( \zeta\)" so we know \(.95\zeta=10\) or \(\zeta =\frac{10}{.95}\)

Answer 64

Yeah got it..

Answer 65

then we want 15% less that \(\zeta\) so we want \(.85\times \frac{10}{.95}\) whatever that is

Answer 66

but i dont believe in you anymore @waterineyes

Answer 67

15 not 15%..

Answer 68

are you serious

Answer 69

Okay @nickhouraney

Answer 70

http://www.wolframalpha.com/input/?i=8.5%2F.95

Answer 71

@nickhouraney it is not 23% of something because percents do not work that way. the operation is multiplication not addition
for example, to find 15% of some number you multiply by \(.15\)
to increase a number by 15% you multiply by \(1.15\)
to decrease a number by 15% you multiply by \(.85\)

Answer 72

i got you @satellite73 the wording is very confusing on this one (for me at least)

Answer 73

it is very confusing, yes.
english is not math
and percent wording is often ambiguous

Answer 74

But we have to find:

\[\zeta - 15\]

Answer 75

ooh i see, thought it was 15% less than \(\zeta\)

Answer 76

That will give you the answer negative..
We all have tried it earlier..

Answer 77

i also assumed it was 15% but @sauravshakya isnt even here to verifu

Answer 78

But he said question is right and answer choices are 1, 2, 3 and 4..

Answer 79

and i refuse to think anymore at this point lol

Answer 80

\(.95\times \zeta=10\iff \zeta=\frac{10}{.95}\) so i guess you want \(\zeta-15=\frac{10}{.95}-15\) a totally different number

Answer 81

Yes this will be negative first of all..

Answer 82

ya so you had it right the first time

Answer 83

choices are 1,2,3 or 4?
then i must have really misread the problem

Answer 84

Yes choices are 1,2 3, and 4..

Answer 85

And Suarav is an intelligent guy I don't think he would be in a mood here to fool us..

Answer 86

???

Answer 87

Nothing..

Just kidding..

Answer 88

Did you get the solution how to solve it ??

Answer 89

That was the question from a engineering college.... That was given to me by a friend

Answer 90

Nope

Answer 91

Then it is big shame on me..

Answer 92

I just asked because if you got then do tell me how to solve it..

Ha ha ha..

Answer 93

yes if you do ever figure it out show us

Answer 94

I still think that we are unable to convert very first line correctly into mathematics..

Answer 95

@experimentX can u plz see this

Answer 96

hold on!!