Please explain these few questions properly, step by step.
1)55% of students in a school are boys and the number of girls are 810. Find the total number of students and the number of girls.
2)Find a number which:
i) When increased by 10% becomes 77.
ii) When increased by 8% becomes 115.
3)Aditya's income is 20% less than that of Arnav. How much percent is Arnav's income more than Aditya's income?
4)The price of sugar increases by 20%. By what percentage should a housewife reduce consumption so that her expenditure does not increase?
5)At what rate percent will a sum of money double itself in 8 years?
Please explain properly! Thankyou.
Due to paucity of time, we are unable to solve all your queries. We are solving some of them.
Q1. The answer posted by @Shivangi64 for the first part is correct. Keep it up Shivangi. Continue the hard work.
Q3. Let Arnav`s income be 100.
So, Aditya`s income =
Arnav`s income is 20 more than that of Aditya`s =
Expenditure = consumption × price
Let price of sugar be 100
Expenditure = consumption × 100
⇒expenditure = 100 × consumption 1
When the price of sugar increases by 20%,
the new price = 100 + 20%(100) = 100 + 20 = 120.
Expenditure = 120 × consumption 2
Since the consumption remains constant,
100 × consumption 1 = 120 × consumption 2
⇒ consumption 2 = consumption 1
Thus, the decrease in consumption =
ok then the comes here:
1. the no. of girls is 810.
The percentage of girls in the class is 100-55 = 45%
let the total no. of students be x.
45/100 *x =810
x= 810*100/45 = 1800
so yhe total no. of students is 1800
the total no. of boys= 55/100 * 1800 = 990
2. i) let the unknown no. be x.
100+10/100 * x= 77
x = 77*100/ 110 = 70.
ii) let the unknown no. be x
100+8/100* x =115