Question

19. A number is increased by 20% and the increased number is decreased by 20%. Find the net
increase or decrease per cent.
20. The salary of an officer is increased by 20%. By what percentage should the new salary be
reduced to restore the original salary?​

Answer 1

Answer:

3 tan=4 find the value of 4sin-3cos/5cos+2cos

Answer 2

Answer:

19.16⅔% 20.16⅔%

Step-by-step explanation:

19.A number is increased by 20%

and the increased number is

decreased by 20%

Let the number be 100

Therefore, the increased no.

=(100+20/100×100)=120

The no.when decreased by 20%

=(120-20/120×100)=310/3

Therefore, decreased percentage

=(120-310/3-)/100×100%=50/3%

=16⅔%

20.The salary of an officer is

increased by20%.

Let the original salary be 100

Therefore, the increased salary

=(100+20/100×100)=120

Therefore, the percent should the

new salary be reduced to restore

the original salry

={100-(100/120×100)}%

={100-250/3}%

=50/3%

=16⅔%