M4maths Previous Puzzles

11 May 2011 Percentage

10 % of x + 20 % of x/2 + 30 % of x/3 + 40 % of x/4 +...............
.........................+ 100 % of x/10 =

OPtion

1) 0.5 x
2) 0.75 x
3) 0.9 x
4) 1 x
5) 1.2 x
6) 1.5 x
7) 1.8 x
8) 2.4 x
9) 2.8 x
10) 3 x

Solution

There are 10 terms in the expression and each term is equal to x/10
for example 40 % of x/4 = (x/4)*(40/100) = x/10
Sum of all 10 terms = 10*(x/10) = x

Correct Option: 4 Best Solution (9)

Dolly   14 years AGO

10 % of x + 20 % of x/2 + 30 % of x/3 + 40 % of x/4 +...............
.........................+ 100 % of x/10 =

10* 0.1*x=1x

Like? Yes (5) | No (3)  

Dr.Dipin Singh   14 years AGO

10 % of x + 20 % of x/2 + 30 % of x/3 + 40 % of x/4 +...............
.........................+ 100 % of x/10 =

10 % of x + 10 % of x + 10 % of x + 10 % of x +...............
.........................+ 10 % of x= 10*10% of x = 100% of x = 1x .. option 4

Like? Yes (5) | No (5)  

Balakumaran N.A   14 years AGO

the sequence going, x/10+x/10+... up to 10 times...
10x/10=1 x...

Like? Yes (3) | No (4)  

dharmaveer   14 years AGO

10 % of x + 20 % of x/2 + 30 % of x/3 + 40 % of x/4 +...............
.........................+ 100 % of x/10 = 0.1x + 0.1x ..... +0.1x (total 10) = 1.0x

so, option 4.

Like? Yes (2) | No (3)  

Karthick Babu   14 years AGO

10 % of x = 10x/100=x/10
20 % of x/2 = 10x/100=x/10
30 % of x/3 = 10x/100=x/10....
...like this going
So 10 times comes x/10= 10 * x/10 = x
So ans is 1 x (Opt 4).

Like? Yes (2) | No (4)  

Seema   14 years AGO

(10/100)*x+(20/100)*x/2+(30/100)*x/3.....+(100/100)*x/10

each term reduces to (10/100)*x such 10 terms are der
so (10*10)/100*x=1x

Like? Yes (1) | No (3)  

KALPANA G   14 years AGO

10x/100 + 20x/200 + 30x/300 + 40x/400 + ........ +100x/1000 = x/10(1+1+1+........1(10 times))=x/10(10)=x

Like? Yes (2) | No (4)  

Mounika Chowdary   14 years AGO

its simple 10%of x is 0.1x then 20% of x is 0.1 x then add u will get 10x0.1x=1x

Like? Yes (1) | No (3)  

Penkay Sundeep   14 years AGO

1/10(10x)
=1x

Like? Yes (1) | No (3)