Aptitude - Questions & Answers

Progression - Online Quiz

Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Progression. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - What number of term arrives in the A.P. 7, 11, 15..... 139?

Answer : B

Explanation

Here a = 7 and d = (11-7) = 4
Let there be n terms in the given A.P. then,
Tn = 139 ⇒a+ (n-1) d =139
⇒ 7+ (n-1)*4 = 139 ⇒ (n-1) *4 = 132 ⇒ (n-1) = 33
⇒ n = 34

Q 2 - In the event that 2x (x+10) and (3x +2) are in A.P. at that point x=?

Answer : C

Explanation

Since 2x, (x+10) and (3x+2) are in A.P. we have
(x+10)-2x = (3x+2)-(x+10) ⇒ 10-x =2x-8 ⇒ 3x= 18 ⇒ x= 6

Q 3 - What number of products of arrive between the whole numbers 15 and 105, both comprehensive?

Answer : B

Explanation

Requisite no. are 15, 18, 21, 24, 105.
Here a = 15 and d = (18-15) = 3
Let their number be n. Then,
a + (n-1) d =105 ⇒ 15+ (n-1)*3 = 105
⇒ a+ (n-1) d = 105 ⇒ 15+ (n-1)*3 = 105
⇒ (n-1)*3 = 90   ⇒ n-1 =30 ⇒ n = 31

Q 4 - (45+46+47....+113+114+115)?

Answer : D

Explanation

Here a=45, d =1 and L=115.
A+ (n-1) d = 115 ⇒ 45+ (n-1) *1 = 115
(n-1 ) = 70 ⇒ n = 71
Sum = n/2 * (a+L) = 71/2 * (45 +115) = 71/2 *160 = (71 *80) = 5680.

Q 5 - The total of initial 20 odd regular numbers is:

Answer : C

Explanation

Sum = (1+3 +5+7+...to 20 terms
Here a = 1, d = (3-1) =2 and n = 20.
∴ Sṇ = n/2 {2a + (n-1) d} =20/2 *{2*1+ (20-1)*2} =10*40=400.

Q 6 - Which term of the G.P. 5,10,20,40 ...is 1280?

Answer : B

Explanation

Let T_n = 1280. Then ar (ⁿ⁻ⁱ) = 1280 ⇒ Here a= 5 and r =2
∴ 5*2(ⁿ⁻ⁱ) =1280 ⇒256 = 2(ⁿ⁻ⁱ) =2⁸ ⇒ n-1 =8 ⇒ n= 9

Q 7 - In the event that a ≠b, Then which of the accompanying proclamations is valid?

Answer : C

Explanation

For any two unequal numbers a and b, we have (A.M).> (g.m)
∴   (a+b)/2 > √ab

Q 8 - A man heaps logs of wood so that the top layer contains one log and every lower layer has one more than the layer above. In the event that there are 15 layers, the aggregate number of logs will be:

Answer : B

Explanation

Total number of logs = 1+2+3+...+15.
This is an A.P. in which a =1, d =1 and n= 15.
Sn = n/2(a+1) = 15/2 (1+15) =120

Q 9 - The number of inhabitants in microbes, society copies ever 2 minutes. How long will it take for the populace to develop from 1000 to 512000 microbes?

Answer : D

Explanation

Let the growth be 1000, 2000, 4000 ...512000.
This is a G.P. in which a = 1000, r = 2 and tn = 512000
Tn = ar&n-1 ⇒ 1000*2 &n-1 = 512000⇒ 2 &n-1 = 512= 2⁹ ⇒ (n-1) = 9.
∴ Time taken = (2*9) min = 18 min.

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