Question
The ratio of the speed of boat in upstream to speed of
boat in downstream is 7:9. If the boat can cover a total of 70 km upstream and 90 km downstream in 5 hours, then find the time taken by the boat to cover 200 km in still water.Solution
Let speed of boat in upstream and downstream be ‘7x’ km/h and ‘9x’ km/h respectively. 70/7x + 90/9x = 5 10/x + 10/x = 5 20 = 5x x = 4 Speed of boat in still water = (7x + 9x)/2 = 8x = 8 × 4 = 32 km/h Desired time = 200/32 = 6.25 hours
If '#' means ' - ', '@' means '+', '$' means '÷' and '&' means ' X ', then what is the value of the following expression?
72 # 91 $ 7 & 4 @ 18
If ‘@’ denotes ‘addition’, ‘%’ denotes ‘multiplication’, ‘&’ denotes ‘subtraction’ and ‘#’ denotes ‘division’, then what...
If “+” means “minus”, “×” means “divided by”, “÷” means “plus”, and “-“ means then “multiplied by”
250 × 10 �...
After interchanging the given two signs, what will be the value of the given equation?
Sign: + and ÷
Equation: 54 - 22 X 198 + 9 ÷ 420
Select the different combination of mathematical signs that can sequentially replace the # sign and balance the given equation.
63 # 9 # 52 # 10 # 4 = 19
Select the correct combination of mathematical signs that can sequentially replace the * signs and balance the given equation.
44 * 392 * 7 * 11 ...
Select the correct combination of mathematical signs that can sequentially replace '*' sign and balance the equation given below.
432 * 6 * 9 * 1...
A seller sold a vehicle for Rs. 81,000 with the loss of 10%. At what price be sold to earn 10% profit?
Which two signs should be interchanged to make the following equation correct?
52 – 27 ÷ 9 + 7 × 5 = 20
Select the correct combination of mathematical signs that can sequentially replace '*' sign and balance the equation given below.
172 * 224 * 8 *...
Relevant for Exams:
