Answer:
Step-by-step explanation:
a.
first number is 1000-1+9=1008
9)1000(1
9
-------
10
9
-----
10
9
----
1
----
last number is 9999
9| 9999
---------
1111 |0
--------
9999=1008+(n-1)9
9999-1008=(n-1)9
n-1=8991/9=999
n=999+1=1000
b.
first digit=1000
last digit=9999-1=9998
2 |9999
---------
|4999|1
9998=1000+(n-1)2
(n-1)2=9998-1000=8998
n-1=4499
n=4499=1=5000
c.not sure
d.
total numbers=9000
9999=1000+(n-1)1
9999-1000=n-1
n=8999+1=9000
numbers divisible by 3=3000
first number=1002
last number=9999
9999=1002+(n-1)3
(n-1)3=9999-1002=8997
n-1=2999
n=2999+1=3000
numbers not divisible by 3=9000-3000=6000
e.
numbers divisible by 5=1800
first number=1000
last number=9995
9995=1000+(n-1)5
(n-1)5=9995-1000=8995
n-1=1799
n=1799+1=1800
numbers divisible by 7=1286
7 | 1000
---------
| 142-6
1000-6+7=1001
7 | 9999
|---------
1428-3
9999-3=9996
first digit=1001
last digit=9996
9996=1001+(n-1)7
(n-1)7=9996-1001=8995
n-1=1285
n=1285+1=1286
numbers divisible by 35=257
first digit=1015
35 ) 1000 ( 28
70
----
300
280
------
20
---
1000-20+35=1015
35)9999(285
70
----
299
280
-----
199
175
----
24
----
last digit=9999-24=9975
9975=1015+(n-1)35
(n-1)35=9975-1015=8960
n-1=8960/35=256
n=257
reqd. numbers=1800+1286-257=3019
The ratio of one triangle to the other (because they are similar, since the top angles are both 44 degrees and the two sides on the other sides of them are the same) is 12:8, or 3:2.
So therefore, we can say it's 9:6, so DE is 6.
The A/= it means the answer is okay.
