Question
In a class, the ratio of number of boys to number of
girls is 12:11. If 3 boys joined the class and 1 girl left the class, then the ratio becomes 7:6. Find the actual number of girls in the class.Solution
Let initially the number of boys and girls be 12x and 11x, respectively.
(12x + 3) : (11x − 1) = 7 : 6
Or, 6(12x + 3) = 7(11x − 1)
Or, 72x + 18 = 77x − 7
Or, 5x = 25 ⇒ x = 5
Therefore, number of girls = 11 × 5 = 55Â
Praveen earned an interest of Rs. 10,400 by investing a certain sum with bank C under scheme III for two years. How much interest he would have earned h...
The difference between total SI earned on Rs 'P' at 18% p.a. for 3 years and total CI earned on same sum at 20% p.a. for 2 years when compounded annuall...
Farhan invested a certain amount of money 8 years ago. He put his money at the rate of 5% for the first 2 years, 7% per annum for the next 4 years and ...
Suppose a man invested Rs.(4000 + 2a) in Mutual Fund 'X' for 2 years and Rs. (3200 + 6a) in scheme 'Y' for 2 years and interest gets from Mutual Fund 'X...
Mr. Raman invested Rs. 45,000 with Bank A under the scheme II for 3 years. How much amount he will get on maturity?
A sum of Rs.20,000 is invested partly with Bank B under scheme III and remaining with Bank D under scheme IV for 1 year. If the total interest earned is...
Suppose a man invested an amount in the ratio of 3 : 2 at the rate of (r – 1)% & (2r – 16)% respectively at simple interest. If bigger amount invest...
₹4,300 becomes ₹4,644 in 2 years at simple interest. Find the principle amount that will become ₹10,104 in 5 years at the same rate of interest.
The SI unit of acceleration is_________.
A person sells an article at 10% below its cost price. Had he sold it for ₹332 more, he would have made a profit of 20%. What is the original selling ...
Relevant for Exams:
