691. If the number obtained on interchanging the digits of a two-digit number is 18 more than the original number and the sum of the digits is 8, then what is the original number ?
A. 26
B. 35
C. 53
D. Cannot be determined

692. A two-digit number is such that the product of the digits is 8. When 18 is added to the number, then the digits are reversed. The number is :_________?
A. 18
B. 24
C. 42
D. 81

693. Find the number which when multiplied by 15 is increased by 196.
A. 14
B. 20
C. 26
D. 28

Explanation:
Let the number be x. Then, 15x – x = 196
14x = 196 x = 14.

694. The sum of the squares of three numbers is 138, while the sum of their products taken two at a time is 131. Their sum is :___________?
A. 20
B. 30
C. 40
D. None of these

695. Three numbers are in the ratio of 3 : 4 : 6 and their product is 1944. The largest of these numbers is :___________?
A. 6
B. 12
C. 18
D. None of these

Explanation:
Let the numbers be 3x, 4x and 6x.
Then, 3x x 4x x 6x = 1944 72×3 = 1944
x3 = 27 ,=> x = 3
∴ Largest number = 6x = 18,

696. If the sum of a number and its square is 182, what is the number ?
A. 15
B. 26
C. 28
D. 13

Explanation:
Let the number be x.
Then, x + x2 = 182 x2 + x – 182 = 0
(x + 14) (x – 13) = 0 x = 13.

697. The sum of two numbers is 25 and their difference is 13. Find their product :
A. 104
B. 114
C. 315
D. 325

Explanation:
Let the numbers be x and y. Then, x + y = 25 and x – y = 13.
4xy = (x + y)2 – (x – y)2 = (25)2 – (13)2 = 625- 169 = 456
=> xy = 114.

698. If the sum of two numbers is 33 and their difference is 15, the smaller number is :__________?
A. 9
B. 12
C. 15
D. 18

Explanation:
Let the numbers be x and y.
Then, x + y = 33 …(i)
and x – y = 15 …(ii)
Solving (i) and (ii), we get : x = 24, y = 9.
∴ Smaller number = 9.

699. A man goes to his office from his house at a speed of 3 km/hr and returns at a speed of 2 km/hr. If he takes 5 hours in going and coming, what is the distance between his house and office?
A. 3 km
B. 4 km
C. 5 km
D. 6 km

700. A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.
A. 121 km
B. 242 km
C. 224 km
D. 112 km

NOTE
IF YOU THINK ANY OF THE MCQ ABOVE IS WRONG.
PLEASE COMMENT WITH CORRECT ANSWER AND ITS DETAIL EXPLANATION IN COMMENT BOX.
THANK YOU