Question

3. A number is increased by 20%, and, then, it is decreased by 20%. If the final value of the number is 48, then
find the initial value of the number.
102 Marks
4. If a + b = 23 and a
b=7 than​

Answer 1

Answer:

The initial value = 75

Step-by-step explanation:

let the original number = 100

after 1st 20% decrement, the number = 100- 100*(20/100) = 100-20 = 80

after 2nd 20% decrement, the number = 80 - 80*(20/100) = 80-16 = 64

so, the final value = 64

if the final value is 64, the original value is 100

if the final value is 48 (given), then the original value = 100*(48/64)

                                                                                        = 100*(3/4)

                                                                                        = 25*3

                                                                                        = 75

=> the initial value = 75

verification:

Initial value that is arrived = 75

1st decrement, 75- 75*(20/100) = 75 - 15 = 60

2n decrement, 60 - 60*(20/100) = 60 - 12 = 48 (given final value)

verified