We have : 

2 = 1+1

4 = (1 + 2) + 1

7 = (1 + 2 + 3) + 1

11 = (1 + 2 + 3 + 4) + 1

16 = (1 + 2 + 3 +4 + 5) + 1

=> (1 + 2 + 3 + 4 + 5 + 6) + 1 = 22

Answer : 22

Change number 6

We have : 

26 - 63 = 64 - 63 = 1

Answer : 1

10+20+30+40+50+60+70+80+90

=10+90+20+80+30+70+40+60+50

=(10+90)+(20+80)+(30+70)+(40+60)+50

=100+100+100+100+50

=450

7/4=1,75

The positive differences between 3.75 and 7/4 are:

3,75-1,75=2

Answer: 2

There are 2 parts are shaded and the total is 10 parts

=>2/10=1/5 (shaded−sections)

Answer:1/5 shaded−sections

We have:

a/6=b/3=c/12=a-b+c/6-3+12=30/15=2

a/6=2=>a=12

b/3=2=>b=6

c/12=2=>c=24

a/3=b/4=a+b/3+4=14/7=2

a/3=2=>a=6;b/4=2=>b=8

Number of month in 35 years is:

35.12 = 420 (monthsn)

Answer:420 month

Số hồi đáp: 420 tháng

Smaller numbers greater than 20 are: 21
The largest number less than 158 is 157
Odd numbers are:

(157-21):2+1=69

Answer:69

The width of the living room is:

195:15=13(ft)

Answer:13 ft

A=2+4+8+16+32+64+128+256+512+1024=2046

Divisible by 3 is the number of digits divided by 3, then divisible by 3

=> 2046:3

Because, it is a square should we have:

x-2=3

x   =3+2

x   =5

Answer: 5

The value of the height is:

120: 5 = 4 = 120: 20 = 6 (in)

Answer: 6 in

Số phần trăm nho không đỏ là:

100-20=80%

Số quả nho không đỏ là:

50.80%=40 (quả)

Vậy số quả nho không đỏ là 40 quả

 The perimeter of the hexagon is:

6.6=36 (cm)

 The perimeter of this hexagon is: 36cm

10+10=20

Troll

b)8 km /hr

The percent of the burger is:

(120-30):120.100=90:120.100=75%

So choose (D) 75

three wear skirt

1729=7.13.19

=>  The sum of all prime factor of 1729 is:7+13+19=39