Problem Solving

tamara saves $35 each week.
if she now has $100 saved, in how many weeks can she first have enough saved to buy a lawn mower that costs $250?
a)2
b)3
c)4
d)5
e)6


i got e but the answer shows d.

please....

250 (what she needs) - 100 (what she has) = 150 $ (what she still needs)

after 4 weeks she has 140$ 35*4=140
so she needs one week more to arrive at 150, hence 5 weeks

Tamara saves 35$/week
on average 5/day

so til lnow tamara has 100$ saved
that is he has been saving for two weeks(14 days) 6 days



so money which is short is 150$ in how many days

1day---- 5$
xday ---150

5x=150
x=150/5

x=30 days

which is 4 weeks and two days ! i take 5 weeks as the oiption which is D

Thanks
Vishu