Question

A income increased by 20 % and again by 20% by what percent should the increased number be reduced so as to get back the original number

Answer 1

Answer:

• Find the Net %Change when successive percentage increase are applied

• This net % change is the difference of Original No. to the last No obtained after a final percentage increase.

•°• To get back the original No., the Increased No. must be reduced by net % increase.

¶ Effect of %change Increase on a No

When a No. is increased by S%

OR

¶ When a No. is increased successively by a% & b%

Let the original No. = 100

By Straight Line Method Of solving :

[100] ➨ 20%↑ ➨[120] ➨20%↑ ➨ [144]

144 - 100 = 44

100 = 100% => 1 = 1%

•°• 44 = 44%

Net Increase in percent= 44%

Using Formula,

Here, a= b

= 40 + 4

= 44

•°• The Increased No. should be reduced by 44% to get back the original No.

Answer 2

HEY MATE YOUR ANSWER IS HERE

LET THE NUMBER BE 100

1) 20% increase in 100

$= \frac{100}{100} \times 100 + 20 \\ \\ = 120$

2) again 20% increase in 120

$= \frac{120}{100} \times( 100 + 20) \\ \\ = 12\times 12 \\ \\ = 144$

3) NOW WE HAVE TO FIND TOTAL % DECREASE SO WE HAVE TO GET NUMBER 100 BACK SO

$= \frac{100}{144} \times 100 \\ \\ = \frac{10000}{144 } \\ \\ = 69.44\%$

SO UR ANSWER IS 69.44%

THANKS FOR YOUR QUESTION HOPE THIS HELPS

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