1. A sum of money at compound interest amounts to fifth-hold itself in 7 years. In how many years will it be 25 times itself ?

2. A balloon is connected to a meteorological station by a cable of length 200 m, inclined at 60° to the horizontal. Find the height of the balloon from the ground. Assume that there is no slack in the cable.

3. A ladder is placed against a wall such that its foot is at a distance of 2.5 m from the wall and its top reaches a window 6 m above the ground. Find the length of the ladder.

4. There are 45 personnel in an army camp. If the number of personnel increases by 9, the expenses of mess increase by Rs. 54 per day, while the average expenditure per person diminishes by 1. Find the original expenditure of the mess.

5. The ratio of quantity of water in fresh fruits to that of dry fruits is 7 : 2. If 400 kg of dry fruits contain 50 kg of water then find the weight of the water in same fruits when they were fresh?

6. If the ratio of simple interest and principal is 8 ∶ 25/2 and rate of interest is equal to the time invested then find the time of investment?

7. 4 men can develop a mobile app in 3 days. 3 women can develop the same app in 6 days, whereas 6 boys can develop it in 4 days. 3 men and 6 boys worked together for 1 day. If only women were to finish the remaining work in 1 day, how many women would be required?

8. A student rides on a bicycle at 5 km/hr and reaches his school 3 minute late. The next day he increased his speed to 7 km/hr and reached school 3 min early. Find the distance between his house and the school.

9. If the rate of income tax increases by 18%, net income decreases by 2%. What was the rate of income tax?

10. If the profit generated on selling one product produced by A is Rs. 4.5 ,then find the total profit earned on selling all the products of A in all year together.