math questions. Help?

Question

jus ignore the (>). I had to use it to get the right format of the problem.
>750
-DEF
----------
>DEF

Each of the letters D,E,F, represents a different digit in the subtracion problem above. What is the fraction that equals the decimal 0.DEF ?
a) 1/5 b) 1/4 c) 3/8 d) 1/2 e) 3/4

A broken watch loses 2 minutes every 4 hours. How long, in days, will it take the watch to lose 1 hour?
a) 2.5 b) 5 c) 6 d) 7.5 e) 10

Answer 1

Since DEF + DEF = 750, then DEF = 750/2 = 375.

.375 = 3/8, so c.



There are 60 minutes in an hour. The watch loses 2 minutes every four hours, so one minute every two hours.

60 minutes * 2 hours/minute = 120 hours.

120 hours * 1 day/24 hours = 5 days., so b.

Answer 2

We have 750-DEF = DEF, so 750 = 2*(DEF), DEF = 375,
we have three different digits, so we're looking for
0.375. Let's check alternatives:

a) 0.200
b) 0.250
c) 0.375
d) 0.500
e) 0.750

So, that's letter (c)

2)
2 minutes in 4 hours => 1 minute in 2 hours => 60*1 minutes (1 hour) in 60*2 hours, 120 hours
1 day = 24 hours
x days = 120 hours
x = 120/24 = 5 days

So, that's letter (b)

Answer 3

DEF + DEF = 750 so DEF = 375 and 0.375 = 3/8 (c)

2 minutes every 4 hrs.
30 x 2 minutes = 60 minutes (1 hr)
30 x 4 hrs = 120 hrs = 5 days (120/24 = 5)

Answer 4

750/2= 375
.375 in decimal is 3/8
C. 3/8

30 min*4 hr/min= 120hrs /24hrpday= 5 days
B. 5

Answer 5

.DEF= 3/8

Watch=5