Answer:
Step-by-step explanation:
In order to figure out how much money was left in the account after the interest was withdrawn, we have to first find out how much money was initially deposited to earn that amount of interest! The means to find that initial investment is found in the simple interest formula
prt = I, where
p is the initial investement,
r is the interest rate in decimal form,
t is the time in years, and
I is the interest earned. Notice that we have all those things but the p.
Filling in:
p(.0425)(4) = 2380 and
.17p = 2380 so
p = 14000
That means that 14000 was initially invested. If the depositor withdrew the 2380, then
14000 - 2380 is the amount left in the account, namely, $11620
Length of train : 100
length of bridge : 400
distance covered by the train to cross the bridge : (100 + 400) = 500
time taken by the train to cross : 30
speed = distance / time
speed = 500/30
speed = 16.67 meters per second <===
Answer:
Step-by-step explanation:
You do not need to where the formula comes from but, just for fun, here’s a hint
To add up the numbers 1 to 10
Write out the numbers
1 2 3 4 5 6 7 8 9 10
Write them backwards
10 9 8 7 6 5 4 3 2 1
Add up both lists
11 11 11 11 11 11 11 11 11 11
This is 10 × 11 = 110
But this is twice the sum as two lots were added together
So the sum of the numbers 1 to 10 is 110 ÷ 2 = 55
ArSeqSum Notes fig4, downloadable IGCSE & GCSE Maths revision notes