Question

David earned a fixed salary each month. In January, he spent $400 and

saved the rest. In February, he spent 10% more and his savings dropped by
20%. What was David's savings in January?​

Answer 1

$200.

Explanation:

Let his fixed monthly salary be x dollars.

Then he saved x-400 dollars in January.

He spent 10% more in February which is $440 so his savings were x-440 dollars, which is 0.20 less than in January. So we have the equation:

(x - 400) - (x - 440) = 0.20(x - 400)

0.80(x - 400) = x - 440

0.8x - 320 - x = -440

-0.20x = - 120

x = $600

So his saving in January were 600 - 400 = $200.

Answer 2

if he spent %10 more 400.110/100 he spent 440

he spent 40 more and his savings dropped %20 this means 40 is %20 of his total saving 40.5=200