We can set up an equation by translating the word problem above.
Sumitra has to solve 384 questions.
Number of Questions / Questions per day = Days
If Sumitra does not follow her friends suggestions, she will take 384/x days. If she follows her friend’s suggestion of reading 8 more pages per day (x+8) she will take 384/x+8 days. The difference in number of days between both rates is 8.
We can set up an equation as such:
384/x - 384/x+8 = 8
Next,
384(x+8) - 384x = 8(x)(x+8) —> multiple the whole equation by LCM (x)(x+8) to simplify the fractional denominators.
384x + 384(8) - 384x = 8x^2 + 64x
0 = 8x^2 + 64x - 384(8)
0 = x^2 + 8x- 384
0 = (x + 24)(x - 16)
x = -24 or x = 16
Since pages per day cannot be negative, x = 16
Number of days without suggestion:
384/16 = 24 days
Number of days with suggestion:
384/24 = 16 days
24 days - 16 days = 8 fewer days following suggestion
IMO Option D
Posted from my mobile device