The sum of three numbers is 126 and their ratio is 1:2:3 respectively. If the sum of last two numbers is 105 , then find the first number.
Given:
Sum of three numbers = 126
Ratio of the numbers = 1:2:3
Sum of last two numbers = 105
Formula used:
If numbers are in ratio a:b:c, then individual numbers are k × a, k × b, k × c
Total sum = k × (a + b + c)
Solution:
Let the numbers be k × 1, k × 2, k × 3.
Sum of three numbers = k × (1 + 2 + 3) = 126
=> 6k = 126
=> k = 21
Numbers are k×1 = 21, k×2 = 42, k×3 = 63.
Sum of last two numbers = 42 + 63 = 105
First number = 21
∴ The correct answer is option (B).
Find the value of x in the proportion 69 : 23 :: 63 : x.
The ratio of the incomes of A and B is 3 : 5 and the ratio of their expenditures is 2: 3. If the income of A is equal to 6/7 of the expenditure of B, then the ratio of the savings of A and B is :
The ratio of number of boys and girls in a school of 3528 students is 5:4. How many more girls should be admitted in the school to make this ratio 1:1?
If the third proportional of 28 and 70 be x, then what is the value of x?
The cost of 40 packets of 12 pens is ₹1680. The cost of 30 packets each containing 9 pens is
The first, second and fourth numbers in a proportion are 31, 12 and 156 respectively.
The mean proportional between 25 and a number N is two times the mean proportional between 15 and 35.
Compare the ratios 12 : 13, 7 : 8, 9 : 10, and 5 : 6. Which one is greater than 0.9 but smaller than 0.95?
