Amaka buys 4 rulers and a pencil and these cost the same as 2 rulers and 4 pencils. If a pencil cost #8, how much does a ruler cost?

 ruler cost $12

Step-by-step explanation:

step 1

Let cost of ruler  be represented as r

and cost of pencil be represented as p

we were given that

4 rulers and a pencil and these cost the same as 2 rulers and 4 pencils which is expressed as

4r + p = 2r+ 4p

and cost of pencil= $8

therefore

sTEP 2--- Solving

4r+ 8 = 2r+ 4 x8

4r+ 8 = 2r+ 32

4r - 2r= 32-8

2r= 24

r= 24/2 = r= $12

SI=(P*R*T)/100

P=2000

R=1.5

T=6

SI=(2000*1.5*6)/100

=(2000*9)/100

=180

Neil will earn interest of 180

The answer is in the image 

Speed=Distance/time

Here,

distance=15m

time=1sec

speed=15/1=15m/sec

Distance=Speed*time

time=15min=15*60sec=900sec

Distance travelled in 15 min=15*900=13,500m

=13500/1000 km=13.5Km

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

The answer is in the image 

Area of rectangle= L*b

here,

L=12.4 cm

b= 8.8 cm

A= L*b

= 12.4 * 8.8 = 109.12 cm^2

Given height of gymnasium is 5/6 height of 30 foot ball

therefore height of gymnasium=5/6 * 30

=25 feet

The solution is given below