Question

Topic :-
Chapter 5, Application of percentage , brain teasers, question no. 4

Book :-
Mathematicas class 7, DAV school

But Note :-
I want full and proper explanation

Don't be greedy for points

Correct, well explained answer = brainliest

Question 1.
If x% of y is 13x, then find the value of y.

Question 2.
Find 12½% of 3½% of ₹256 .​

Answer 1

Question 1 :

If x% of y is 13x , find the value of y.

Solution :

Given that, x% of y is 13x.

⇒ x% of y = 13x

⇒ x/100 × y = 13x

⇒ xy/100 = 13x

⇒ xy = 13x × 100

⇒ xy = 1300x

⇒ y = 1300x/x

⇒ y = 1300

∴ Value of y = 1300. (Answer)

Question 2 :

Find 12½% of 3½% of ₹256.

Solution :

We have to find, 12½% of 3½% of ₹256.

⇒ 12½% of 3½% of ₹256

⇒ 25/2% of 7/2% of ₹256

⇒ 25/(2 × 100) × 7/(2 × 100) × ₹256

⇒ 25/200 × 7/200 × ₹256

⇒ 1/8 × 7/200 × ₹256

⇒ 7/1600 × ₹256

⇒ 7/100 × ₹16

⇒ 7/25 × ₹4

⇒ ₹28/25 (Answer)

Answer 2

Answer:

$\large \dag$ Solutions :-

• Hi mate ,

• This is @MasterRohith,

$\sf\tt\large{\red {\underline {\underline{\;Question (1):}}}}$

1. If x% of y is 13x, then find the value of y .

$\large \dag$Answer :-

• x% of y =13x

• x/100 × y =13x

• xy/100 = 13x

• xy=13x × 100

• xy =1300x

• y=1300x/x

• y= 1300.

The value of y is 1300.

$\sf\tt\large{\red {\underline {\underline{\;Question(2):}}}}$

• Find 12 1/2% of 3 1/2% of £256

$\large \dag$ Answer :-

• 12( 1/2)% of 3( 1/2)% of $256

• 25/2% of 7/2% of $256

• 25/(2×100) × 7/(2×100) × $256

• 1/8×7/200×$256

• 7/1600×$256

• $28/25.

The value of y is $28/25.

$\large \dag$ Hope it helps u mate :-