# Numbers Questions

Q:

Find the sum to 200 terms of the series 2 + 5 + 7 + 6 + 12 + 7 + ....

 A) 30,400 B) 30,200 C) 34,600 D) 38,400

Explanation:

we can treat every two consecutive terms as one.
So, we will have a total of 100 terms of the nature:
(2 + 5) + (7 + 6) + (12 + 7).... => 7, 13, 19,....

We know the sum of n terms  $\frac{n\left(n+1\right)}{2}$

Now, a= 7, d=6 and n=100
Hence the sum of the given series is
S= 100/2 x[2 x 7 + 99 x 6]
=> 50[608]
=> 30,400.

3 546
Q:

How many digits will be there to the right of the decimal point in the product of 85.44 and .08455 ?

 A) 7 B) 5 C) 4 D) 6

Explanation:

Sum of decimal places = 7.

Since the last digit to the extreme right will be zero (since 4 x 5 = 20), so there will be 6 significant digits to the right of the decimal point.

3 529
Q:

Two bus tickets from city K to L and three tickets from city K to M cost Rs. 77,  but three tickets from city K to L and two tickets from city K to M cost Rs. 73. What are the fares for cities L and M from K ?

 A) Rs. 13 and Rs. 17 B) Rs. 17 and Rs. 19 C) Rs. 23 and Rs. 17 D) Rs. 13 and Rs. 19

Explanation:

If fares for cities L and M from K are x and y respectively, then

2x + 3y = 77 or 6x + 9y = 231...(1)
3x + 2y = 73 or 6x + 4y = 146...(2)

subtracting 2 from 1, we get

5y = 85

y = Rs. 17 => x = Rs. 13

1 475
Q:

K men agree to donate a gift of Rs. L to trust. If three men drop out how much more will each have to contribute towards the purchase of the gift ?

 A) L / (k-3) B) k / (L-3) C) 2K / 3L-K D) 3L / K(K-3)

Explanation:

Intial contribution = L/K
After 3 men drop, then contribution =L/K-3
The amount more to pay in contribution =

$\frac{3L}{K\left(K-3\right)}$

2 468
Q:

What least number must be substracted from 627349 so that the remaining number is divisible by 15 ?

 A) 1 B) 2 C) 3 D) 4

Explanation:

On dividing 627349 by 15, we get remainder = 4.
Therefore, the obtained remainder is the least number to be subtracted from the given number so that the the mnumber is divisible by 15.
Here 4 is the least number to be subtracted from 627349 so that it is divisible by 15.

3 465
Q:

Find the next number in the series 141,137,146,130,155,119,...

 A) 147 B) 168 C) 162 D) 182

Explanation:

The pattern is -4, +9,-16, +25, -36

The next number=119+49=168

4 453
Q:

The difference between two numbers is 3355. When the larger number is divided by the smaller one, the quotient is 6 and the remainder is 15. The smaller number and larger number respectively ?

 A) 546, 3901 B) 415, 3770 C) 668, 4023 D) 404, 3759

Explanation:

Let the smaller number be k.
Then, larger number = (3355 + k)
Therefore 3355 + k = (6k + 15)
‹=› 5k = 3340
‹=› k = 668.

Therefore, the smaller number k = 668 and now the larger number = 3355+668 = 4023.

3 448
Q:

(3x + 2) (2x - 5) = ax² + kx + n. What is the value of  a - n + k ?

 A) 4 B) 1 C) 5 D) 3

Explanation:

(3x + 2) (2x - 5) = $a{x}^{2}+kx+n$ ...............(1)

But (3x + 2)(2x - 5) = $6{x}^{2}-11x-10$........(2)

so by comparing (1) & (2),

we get a= 6, k= -11 , n= -10

(a - n + k) = 6 + 10 - 11 = 5.