In an alloy, aluminium and tin are in the ratio of 4 : 5. In the second alloy, the ratio of same elements is 4 : 7. If equal quantities of these two alloys be mixed to form a new alloy, then what will be the ratio of both of these elements in the new alloy?
Deepinder lent Rs 8200 to Jairaj for 16 years and Rs 4900 to Karna for 15 years on simple interest at the same rate of interest and received Rs 19446.5 in all from both of them as interest. The rate of interest per annum is:
There are 1400 students in a school, 25% of those wear spectacles and 2/7 of those wearing spectacles are boys. How many girls in the school wear spectacles?