Question

3. The Lawrence family must drive an average
of 250 km per day to complete their seven-
day vacation on time. During the first six
days, they travelled 220 km, 300 km, 210 km,
255 km, 240 km and 250 km. How many
kilometres must they travel on the seventh
day in order to finish their vacation on time?​

Answer 1

Given :

(1) Average distance to be covered per day to complete 7day vacation on time = 250km

(2) Distance traveled by them in first 6 days

1. 220 km
2. 300 km
3. 210 km
4. 255 km
5. 240 km
6. 250 km

To find :

Distance they must travel on 7th day to complete vacation on time

Formula used :

Average = Sum of observation ÷ number of observation

Procedure :

• Firstly we will find the total distance they have to travel in 7 days
• Then we will find the distance traveled by them in first six days
• Then will subtract distance traveled in first six days from total distance to be traveled

Solution :

( Let : Total distance = x )

We know that vacation is of 7 days , so Number of days (observation) = 7

Also average = 250 KM

Total distance = x = sum of observation

Therefore using, Average = Sum of observation ÷ number of observation

We get,

$\sf \implies \: 250 \: = \dfrac{x}{7} \\ \\ \sf \implies \: x = 250 \times 7 \\ \\ \sf \implies \: x = \bold{1750 \: km}$

Now we have to find distance traveled in first six days,

➝ Distance traveled in first six days = 220 km + 300km + 210 km + 255 km + 240 km + 250 km

➝ Distance traveled in first six days = 1475 km

Now , Distance to be traveled in last day to complete vacation on time ,

➝ Total distance = Distance traveled in first six days + Distance to be traveled in last day

➝ Distance to be traveled in last day = 1750 km - 1475 km

➝ Distance to be traveled in last day = 275 km

ANSWER :

Distance to be traveled in last day to complete vacation on time = 275km

Answer 2

$\huge\underline{\bf \orange{AηsωeR :}}$

We know that vacation is of 7 days , so Number of days (observation) = 7

Also average = 250 KM

Total distance = x = sum of observation

Therefore using, Average = Sum of observation ÷ number of observation

We get,

=> 250 = x/7

=> x =250×7

=> x =1750km

Now we have to find distance traveled in first six days,

=> Distance traveled in first six days = 220 km + 300km + 210 km + 255 km + 240 km + 250 km

=> Distance traveled in first six days = 1475 km

Now , Distance to be traveled in last day to complete vacation on time ,

=> Total distance = Distance traveled in first six days + Distance to be traveled in last day

=> Distance to be traveled in last day = 1750 km - 1475 km

=> Distance to be traveled in last day = 275 km. Ans.