Q 21 :

In a potato race, a bucket is placed at the starting point, which is 5 m from the first potato.
The other potatoes are arranged 3 m apart in a straight line, with a total of ten potatoes, as shown in the figure.

A competitor starts from the bucket, picks up the nearest potato, runs back to the bucket to drop it in, then returns to pick up the next potato.
This process continues until all the potatoes are in the bucket

 

Based on the above information answer the following questions:

 

(i) What is the distance covered to pick up the 7th potato?

  • 46 m

     

  • 44 m

     

  • 45 m

     

  • 41 m

     

(1)

Distance covered to pick up the 1st potato  =2(5m) = 10m

Distance between two successive potatoes = 3 m

Distance covered to pick up the 2nd potato =2(5+3)=16m

Distance covered to pick up the 3rd potato =2(5+3+3)=22m

So the distances are: 10, 16, 22, …

This forms an AP where: a=a1=10,a2=16,d=16-10=6

Distance covered to pick up 7?? potato  =2(5+6×3)=2×23=46 m



Q 22 :

In a potato race, a bucket is placed at the starting point, which is 5 m from the first potato.
The other potatoes are arranged 3 m apart in a straight line, with a total of ten potatoes, as shown in the figure.

A competitor starts from the bucket, picks up the nearest potato, runs back to the bucket to drop it in, then returns to pick up the next potato.
This process continues until all the potatoes are in the bucket

 

Based on the above information answer the following questions:

 

(ii) If the X-axis represents the complete trip from bucket to nth potato and  Y-axis represents the cumulative distance covered by the girl, then find the Y-coordinates of the 10th potato.

  • 350

     

  • 370

     

  • 330

     

  • 340

     

(2)

Sn=n/2[2a+(n-1)d]S10=10/2[2(10)+(10-1)6]=5[20+54]=5×74=370 m

 

So the y-coordinate of the 10th potato is 370
and the point will be (10, 370).



Q 23 :

In a potato race, a bucket is placed at the starting point, which is 5 m from the first potato.
The other potatoes are arranged 3 m apart in a straight line, with a total of ten potatoes, as shown in the figure.

A competitor starts from the bucket, picks up the nearest potato, runs back to the bucket to drop it in, then returns to pick up the next potato.
This process continues until all the potatoes are in the bucket

 

Based on the above information answer the following questions:

 

(iii) (a) If the average speed of girl is 5 m/s then find the average time taken by girl to put all the potatoes in the bucket?

  • 74 Second 

     

  • 72 Second 

     

  • 75 Second 

     

  • 70 Second 

     

(1)

Average speed of the girl = 5 m/s
Total distance covered = 370 m

Speed=Distance /TimeTime=Distance/Speed =370/5=74 seconds  

 



Q 24 :

In a potato race, a bucket is placed at the starting point, which is 5 m from the first potato.
The other potatoes are arranged 3 m apart in a straight line, with a total of ten potatoes, as shown in the figure.

A competitor starts from the bucket, picks up the nearest potato, runs back to the bucket to drop it in, then returns to pick up the next potato.
This process continues until all the potatoes are in the bucket

 

Based on the above information answer the following questions:

 

(iii) (b) What is the total distance the competitor has to run?

  • 370 m

     

  • 350 m

     

  • 360 m

     

  • 330 m

     

(1)

Let the total distance run by competitor be S.So S = 10/2 [2a + (101)d]= 5 [2a + 9d]= 5 [2 × 10 + 9 × 6]= 5 (20 + 54)            = 370 m The competitor has to run 370 m.

 



Q 25 :

Computer Animations: The animation on a new computer game initially allows the hero of the game to jump a (screen) distance of 10 inch over booby traps and obstacles. Each successive jump is limited to 3/4 inch less than the previous one.

Based on the above information, answer the following questions:

 

(i) Find the length of the seventh jump

  • 512inch

     

  • 412inch

     

  • -512inch

     

  • 432inch

     

(1)

Find the length of the thirteenth jump.

As the hero of the game initially jumps 10 inch and each successive jump is limited to 3/4 inch less than the previous one.

Therefore, we have

Distance covered in first jump = 10 inch

Distance covered in second jump = 10 − 3/4 = 37/4 inch

Distance covered in third jump = 37/4 − 3/4 = 34/4 inch and so on.

Clearly, these distances form an AP with a = 10 and d = −3/4

Length of 7th jump, a = a + 6d= 10 + 6 × (3/4)     = 10  9/2     = (20  9)/2= 11/2 inch = 512 inch.



Q 26 :

Computer Animations: The animation on a new computer game initially allows the hero of the game to jump a (screen) distance of 10 inch over booby traps and obstacles. Each successive jump is limited to 3/4 inch less than the previous one.

Based on the above information, answer the following questions:

 

(ii) Find the total distance covered after seven jumps.

  • 5412 inch

     

  • 5414 inch

     

  • 5421 inch

     

  • -5412 inch

     

(2)

Total distance covered after seven jumps is given by

S7=7/22×10+(7-1)×(-3/4)[Sn=n/2(2a+(n-1)d)]S7=7/2(20-6×3/4)=7/2(20-9/2)=7/2×31/2=217/4=54 1/4 inch."

 



Q 27 :

Computer Animations: The animation on a new computer game initially allows the hero of the game to jump a (screen) distance of 10 inch over booby traps and obstacles. Each successive jump is limited to 3/4 inch less than the previous one.

Based on the above information, answer the following questions:

 

(iii) (a) Find the length of the ninth jump

  • 2 inch

     

  • 1 inch

     

  • 4 inch

     

  • 5 inch

     

(3)

Length of 9th jump a9=a+8d=10+8(-3/4)=10-6=4 inch 

 



Q 28 :

Computer Animations: The animation on a new computer game initially allows the hero of the game to jump a (screen) distance of 10 inch over booby traps and obstacles. Each successive jump is limited to 3/4 inch less than the previous one.

Based on the above information, answer the following questions:

 

(iii) (b) Find the length of the thirteenth jump.

  • 2 inch

     

  • 4 inch

     

  • 3 inch

     

  • 1 inch

     

(4)

Length of 13th jump a13=a+12d=10+12(-3/4)=10-9=1" inch" 

 



Q 29 :

A road roller, often called a roller compactor or just a roller, is an engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar machines are also used in landfills or agriculture. Past records of a road roller manufacturing company show that the number of products produced forms an arithmetic progression (AP).
The company produced 270 road rollers in the 4th year and 510 in the 10th year.

Based on the above information, answer the following questions

 

(i) What was the company’s production in first year?

  • 150

     

  • 140

     

  • 120

     

  • 110

     

(1)

Let a and d be the first term and common difference of the AP formed by the number of products produced by the company every year.

We have:

 a4=270a+3d=270 ...(i)"Also, a10=510a+9d=510...(ii)"Subtracting (i) from (ii): 6d=240d=240/6=40Substituting d=40in (i):a+3×40=270 a=270-120=150Production in first year = 150.

 



Q 30 :

A road roller, often called a roller compactor or just a roller, is an engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar machines are also used in landfills or agriculture. Past records of a road roller manufacturing company show that the number of products produced forms an arithmetic progression (AP).
The company produced 270 road rollers in the 4th year and 510 in the 10th year.

Based on the above information, answer the following questions

 

(ii) What was the company’s production in the 8th year?

  • 430

     

  • 420

     

  • 415

     

  • 410

     

(1)

Company’s production in 8th year is given by:

a8=a+7d=150+7×40=150+280=430