dhoran 7 vigyan paper 2022,std 7 science paper solution 2022,ધોરણ 7 વિજ્ઞાન વાર્ષિક પેપર સોલ્યુશન 22

Find the area of a coloured paper used to stick to a sphere of radius 7 cm.

(a) How is pH paper used to find the pH of a solutions? (b) The pH value of water is 7. What will be the pH value of (i) aqueous solution of sodium hydroxide and (ii) dil HCl.

Q.22 write three solutions for the equation 7x-8y=13

A circle with radius 10 cm is drawn somewhere on a rectangular piece of paper of dimensions 40 cm xx 30 cm. This paper is kept horizontally on table top and a point is marked on the rectangular paper without seeing towards it. Find the probability that it will marked outside the circle. ("Take "pi=(22)/(7))

Four equal sized maximum circular plates are cut off from a square paper sheet of area 784 sq. cm. The circumference of each plate is (Take pi = (22)/(7) )

A student took five papers in ail examination, where hill marl were same on each paper. Her marks in these papers were in the proportion of 6:7:8:9:10. In all these papers together, the candidate obtained 60% of the total marks. Then the number of papers in which she got more than 50% marks is 2 b. 3 c. 4 d. 5 e. none of these

The results of an examination in two papers A and B for 20 candidates were recorded as follows.8passed in paper A,7 passed in paper B,8 failed in both the papers A and B. If one is selected at random,the probability that the candidate has failed in A or B is