Numeracy Test help

Question

Todays share price is 9% lower than yesterday. Today is $1586. So I calculated 1586/0.90 to get $1762.22. HOWEVER, the answer says the calculation is $1585/0.91 to get $1742.86. Can anyone tell where how 0.90 became 0.91 in the calculation?

Answer 1

Today's share price is 9% lower than yesterday. Make "yesterdays price" =x. So, the equation is:

$1586 = x - .09x

 

$1586 = (1-.09)x

$1586 = .91x

$1586/,91 = x

 

Hope that explains it for you.