plzzzzz ans.my ques no6 and 7
Answers
Answer(6):-
Let us assume x and y are the two digits of the number
Therefore, two-digit number is = 10x + y and the reversed number = 10y + x
Given:
x + y = 12
y = 12 – x -----------1
Also given:
10y + x - 10x – y = 18
9y – 9x = 18
y – x = 2 -------------2
Substitute the value of y from eq 1 in eq 2
12 – x – x = 2
12 – 2x = 2
2x = 10
x = 5
Therefore, y = 12 – x = 12 – 5 = 7
Therefore, the two-digit number is 10x + y = (10×5) + 7 = 57
Answer(7):-
(2 men + 7 boys ) do a piece of work in 4 days .
same work done by ( 4 men + 4 boys) in 3 days .
use, M₁D₁ = M₂D₂
where M₁ , M₂ are the number of men and men and D₁, D₂ are the number of days .
(2 men + 7 boys )×4 = (4 men + 4 boys )×3
16 boys = 4 men
1 men = 4 boys
so, (2×4 boys + 7 boys ) do work in 4 days
15 boys do work in 4 days
1 boys does work in 4×15 = 60 days
again,
(4 men + 4×(1/4)men ) do work in 3 days
(4 men + 1 man ) do work in 3 days
5 men do work in 3 days
1 man does work in 3×5 = 15days
HOPE THESE SOLUTIONS HELPS YOU...