The respective ratio between speed of the boat upstream and speed of the boat downstream is 3: 4. What is the speed of the boat in still water if it covers 70 km downstream in 3 hours 30 min ? (in km/h)

Respective ratio between total number of students studying in college A and College B is 5 : 8. In College B, out of the total number of students, 5/8^th are boys, out of which 60% study Commerce and the remaining 800 boys study in other streams. What is the total number of students in College A

A and B started a business with the investments in the ratio of 5 : 3 respectively. After 6 months from the start of the business, C joined and the respective ratio between the investments of B and C was 2 : 3. If the annual profit earned by them was INR 12300/- what was the difference between B’s share and C’s share in the profit

I. x²=49

II. y²-4y-21=0

I. 3x²+16x+21=0

II. 6y²+17y+12=0

I. 8x²+18x+9=0

II. 4y²+19y+21=0