Mathematics MCQs

The ratio of the number of boys and girls in a college is 7 : 8. If the percentage iikcrease in the number of boys and girls be 20% and 10% respectively, what will be the new ratio ?

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A. 8 : 9
B. 17 : 18
C. 21 : 22
D. Cannot be determined
✅ The correct answer is option C. 21 : 22.
Originally, let the number of boys and girls in the college be 7x and 8x respectively. Their increased number is (120% of 7x) and (110% of 8x), i . e . ( 120/100 X 7x ) and ( 110/100 X 8x ) i . e . 42x/5 and 44x/5 Required ratio = 42x/5 : 44x/5 = 21 : 22

A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?

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A. 3.46%
B. 4.5%
C. 5%
D. 6%
✅ The correct answer is option A. 3.46%.
Note: Here, original rate is for 1 year(s); the new rate is for only 4 months i.e.1/3 year(s).